Oswaal NTA CUET (UG)| Question Bank Chapterwise & Topicwise Biology For 2024 Exam [2024 ed.] 9359580473, 9789359580470

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CUET (UG) COMMON UNIVERSITY ENTRANCE TEST

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BIOLOGY Section-l (Domain Speclifc Subject) Strictly as por the Latest Exam Pattern issuod by NTA

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Exam Paper

5 800+ Questions

UNIT I:

Reproduction Chapter-l - Reproduction in Organisms

Chapter-10- Microbes in Human Welfare 110-119

1-10

Chapter-2- Sexual Reproduction in Flowering Plants

11-22

- Human Reproduction Chapter-4 - Reproductive Health Chapter-3

UNIT

23-35 36 - 44

I: Genetics and Evolution

Biotechnology

and its

Applications Chapter11 - Biotechnology: Principles

120-

and Processes Chapter-12

72-84

Chapter-7- Evolution

II: Biology and Human Welfare

Chapter-8- Human Health and Diseases

85-98

Chapter9- Improvement in Food Production 99- 109

UNIT

V:

131

- Biotechnology and Its

Applications

Chapter5- Heredity and Variation 45-57 of Basis Molecular Chapter6 nheritance 58-71

UNIT

UNIT IV:

132- 141

Organisims

&

Environment

Chapter-13- Organisms & Environment

Chapter-14- Ecosystems Chapter-15- Biodiversity and Its

142- 150 151 -161

Conservation

162-171

Chapter-16-

172- 183

Environmental Issues

00

QUESTION PAPER- 2023

dET 3

s National Testing Agency Held on 25n May 2023y BIOLOGY (This includes Questions pertaining to Domain Specific Subject only)

Max. Marks: 200

Time allowed: 45 Minutes

General Instructions: The test is 45 Minutes duration. The test contains 50questions out which 2. of 40 questions needs to be attempted. 8.Marking Scherme of the test: Correct answer or the most appropriate answer: Five marks(+5) b. Any incorrect option marked will be given minus one mark(-1). Unanswered/Marked for Review will be given 100 mark (0). of

a.

G

1. Select the organism which does not undergoes parthenogenesis.

(1)

Honeybee

(2) Rotifer

(3)

Turkey

(4) Fruit fly

2. The method of producing thousands through tissue culture is called as: (1) Somaclones (2) Micro-propagation (3) Somatic hybridisation (4) Vegetative

propagaton-D

Identify the organism which is a source of single cell protein and is grown on commercial scale.

4.

(2)

(3) Azospirillum

(4) Spirulina5

Match List I with List II

of plants

1-5

LIST I A

A. Decomposition is largely oxygen-requiring

C.

(2) A-II, B-I, C-II, D-IV

9

Dry and cold environment favour the

(3) A-II, B-I, C-IV, D-II en(4) A-I, B-II, C-IV,

D-II

6.

Arrange the following events in correct sequence. A.

decomposition.a

B

D. If detritus is rich in lignin and chitin, the decomposition rate is faster.

C.

A and

(2)

Cand

(3) B

B

D

onlybHrsa only

and C only (4) A and D only

Formation of zygote Formation of blastocyst

Implantation

D. Formation of morula

Choose the correct answer from the options given below: (1)

II Polyembryony Albuminous seed IV False fruits

Choose the correct answer from the options given below: (1) A-III, B-II, C-I, D-IV

regarding decomposition?sE

The rate of decomposition is controlled by chemical composition of detritus and climatic factors.

LIST II

IPerisperm

Citrus

3

3. Which of the following statements are correct

B.

Wheat

BBlack pepper cCashew

process.

Rhizobium

(1) Azotobacter

Choose the correct answer from the options given below:

97

n

(1)

Ese

A,D, B,

(2) A, B, D, C (3) A, B, (4)

C,D

C,D, B, A

oSWAAL CUET (UG) C

Chapterese

12 is used to make the bacterial 7. Which of the following up DNA? as Competent cell to take

13.

Match List I with List II

cell

Calcium ion

(2)

() Cartonate ion (3) Sodum ion

(4) Sulphate

ionet4

io

f

D.Turner's Syndrome

dt

incuding carth. ldentify the term associated with the above.

(1) Abiogenesis

(3)

($) Spontaneous generation

14.

Biogenesis

In

separated DNA sel electrophoresis the :

fragments can be visualised (1) In visible light (23 In visible light with staining ) In UV radiation without staining 4) In UV radiation after staining with ethidium bromide

c

Cerical cap II.

D.Vasectomy

IV

12.

Marmmals are able to survive in Antarctica or

Sahara desert as they are (3) Regulators

IV.

Pupaver somniferum

A-I, B-II, C-I, D-IV A-II, B-I, C-III, D-IV (3) A-I, B-II, C-IV D-III

A-IV, B-III, C-I,

D-It

Methanogens do not produce: (1)

Carbon dioxide and methane Methane and Hydrogen (3) Hydrogen and Carbon dioxide (4) Nitrogen and Oxygen The correct sequence of steps involved are: polymerase chain reaction (rCR) is used to extends A. DNA polymerase primers using oligonucleotides. (2)

16.

in the

(2) Partial regulators (4) Migrants

in

the

are denatured. Desired DNA fragments the fragments are ligated with Amplified C vector for cloning. are added D. Oligonucleotides options given correct answer from the B.

A-I, B-1, C-IV, D-II1 AV, B-U, C-M. D-I

(1) Conformers

Cannabis sativa

(1)

Surgical method of sterilisation in human female. Suppress motility of sperms

(2) A-III, B-I, C-IV, D-II (4)

Cocaine

(2)

15.

(1) A-1, B-IV, C-1, D-I (3)

Erythroxvium coca

(4)

Choose the correct answer from the options given below:

Tobacco plant

I

Choose the correct answer fromn the options given below:

Surgical method of sterilisation in human male.

Coppet ions

LIST II

(Obtained from)

Cannabinoids

D.Nicotine

LIST II Barrier method

A-1, B-III, C-IV, D-II

LIST I (Drugs) Heroin

B.

Match List I with List II

ATubectomy

the options oives

Match List I with List II

A

(4)

LIST I

answer from

(4) A-I, B-1V, C-III, D-I

(2) Panspermia

11.

IV.45 +XY/ XX

(1) A-IV, B-II, C-III, D-I (2) A-IV, B-I, C-I, D-II

dN

of life 9. Earty Greck thinkers thought that units planets to different were spores transferred called

10.

II

recesstve trait 44 + XO

Klinefelter'ssyndrome

Choose the correct

(4)

BIOLOGY

Autosomal

C.

below: (3

LIST 44 + XXY

Thalassemia

B.

(2)

(1)

Bark

LISTI

A.Down's syndrome

growth 8. ldentify the equation representing logistic of a population.

Question

Choose the below:

(1)

C, A, B, D

(3)

A, D, B, C

(2) A, C, B, D A, C (4) B, D,

CUET (UG) Exam Paper 2023

17.

13

Select the correct statement/s from

the following: Spermatogonia always undergo meiotic cell division.

A.

8s B.

Primary spermatocytes divide by mitotic cell division. C. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division. D. Spermatozoa are transformed into spermatids. Choose the correct answer fromn the options given

i

t

24.

18.

and C only

A

(3)

D ony

(3) Copper

19.

Drought

(2)

Insects

(3)

Nematodes

(4)

Viruses

(3) A

21.

Population genetics Mendelian genetics (3) Biometrics (4) Molecular genetics (2)

26.

(2)

Hen

(4)

Snail

(3) 28S RNA

earth'

Committee

(GMAC) (3) (4)

Indian Council of Agricultural Research (1CAR) All India Institute of Medical Sciences (AIIMS)

22. Which

of the following is a, hormone releasing

(2) Rain forest of north-east India

(3) Tiaga forest (4) Tundra forest

28.

Inbreeding is carried out in animal husbandry because it: (1) Increase hybrid vigour (2) Improves the breed tor (3) Increase heterozygosity (4) Increase homnozygosity

IUD? (1)

Multiload 375

(2)

LNG-20

(3)

Cervical

29.

Which is known as Terror of Bengal.? Water Lilly

(2) Hydrilla

(3). Water hyacinth

(4). Lantana

(1)

Capsts xiirayitse

(4) Vault

23. The puffed up appearance of dough is due to the production of:

of the planet

?

(1) Amnazon rain forest

b

(GEAC)

Modification Approval l

snRNA (4) 5srRNA

(2)

27. Which forest also known as the 'lungs

Genetic Engineering Approval Committee

(2) Genetic

3

Mature mRNA is a fully processed (1) hnRNA

The organisation sct up by the Indian Government to take decisions regarding the validity of GM research and the safety of introducing" GM organism is: (1)

and D only p² + 2pq+q? =1 represents Hardy (4) B

(1)

determination is found in :

(3)

-

25. (p+)²

E5

female has ZW chromosomes. This type of sex Drosophila Cockroach

and D only

Weinberg equation. It is used in:

20. In some organisms, male has ZZ chromosomes and (1)

Select the statemernts which do not hold true for

Choose the correct answer from the options given below: (1) A and B onlye (2) Band C only

Bt toxin produced by Bacillus thuringiensis is : resistant to (1)

Ethyl alcohol

Cancerous cells show a property of contact inhibition. B. Metastasis is the most feared property of malignant tumors. C. Malignant tumor cells invade and damage the surrounding tissue. D. Malignant tumor cells grows slowly.

Conly (4) Band C only

(4) Nickel

(3)

CO2 gas (4) Pyruvic acid (2)

A.

(2)

Which of the following metal can not be recovered from manual recycling process of e-wastes? (1) Gold (2) Mercury

Oxygen gas

Cancer:

below:

(1)

(1)

30. Threatened animals and plants are taken out from their natural habitat and placed in special settings, protected and given special care is.

oSWAAL CUET

14 (1)

In situ

conservation C.

rk

(3)

Conservation in national

(4)

Conseration in biosphees

D.

LIST I Polygenic traits

LISTI trait of pod Dominant A colour in gardenpea. I.Fleiotropy B. The physical association of two genes on a chromosome. IIL. Vellow C The traits generally controled by three or moe genes When a single gene exhibit IN Linkage multiple phenotypic epression. Green

Choose the corret answer from the options given

below

35.

Sequence the following steps in formation of

Formation of seven cells with eight nuclei. C. Meiosis in megaspore mother cell and formation of megaspore tetrad. D. Functional megaspore undergoes three mitotic divisions, results in formation of eight nudei. B.

B,

D

(4) C,A, B,

D

(2) A,C,

In which process unusual nudeotide methyl guanosine triphosphate) is added to the 5 end of

Cand D Band D

Biofertilises are the organisms that enrich h nutrient quality of the soil. Which of the followine is not a source of biofertiliser? (2)

Fungi (4) Cyanobacteria

ISD

LIST

LIST II

|A.The primates with brain capacty of around 900 cc. |B. The primates with brain

The primates which arose in Africa and moved across continents and developed into distinct

I|Neanderthal

man

Homo crectus

(1) Splicing

(2)

(3) Tailing

(4) Transcripthon factor

Select the incorrect statements

given below.

The Montreal Protocol is associated with

0S

aitenitts IV Australopithecines

650-00 oc and probably did not eat meat.

V|Hono

habilis

Choose the correct answer from the options given below: (1) A-IIL, B-l, C-V, D-II (2) A-IL, B-I, C-IIL, D-V

A-, B-IV, C-III,

S8).

(4) A-I, B-IlL,

37.

C-IV,

D-V

D-|Iotlt

À

38.

a)

Tdentify the gene which is effective against

bore

Capping

A. Methane and Carbon dioide are green house gases.

III| Homo sapiens

raes D. The primates with the brain capacities between

hnRNA.

B.

give

36. Match List I with List II

Choose the correct answer from the options given below:

34.

the options

Asia

female gametophyte of lowering plants A. Cell walls are laid down.

33.

(4)

8) Baculoviruses

C.

(4) A-V, B-IV, C-L, D-u

C,D, A. B

(2)

(1) Bacteria h

0zone depleting

not crucial to dispose off wastes. hospital Dobson units is used to measure water quality

capaityof 1400 cc and lived in east and central

(3) A-IL, B-ILL C-L, D-IV

(3)

of

BIOLOGY

Use of incinerators is

A

B-I, C-L, D-V A-L, B-II, C-V, D-I

(1) A, D, C,B

emission

below: (1) A and B 3) andc

(1) A-M,

32.

of

Choose the correct answer from

Match List I with List lI

(2)

Chapterwise Question Bank

the control substances.

(2) Ex situ onservation

31.

UG)

(1) cryLAC

(2) crylAb

(3)

(4)

crylLAb

zgene

Succession occurring after flood is: (1) Hydrarch succession (2) Primary succession (3) Secondary succession

(4) Mesarch succession

com

CUET (UG) Exam

29

Paper 2023

15

Tdentify the statement which do not hold true for Deoxyribose Nucleic Acid. A.

B.

42.

(1)

Only purine bases are present in DNA. Deoxyribose sugar is present

C. A nitrogenous base is linked to the 1C pentose sugar through N-glycosidic linkage. D. Phosphate group is linked to OH of 4C of a nucleotide.

injecting antigenic preparation (3) injecting preformed antibodies (4) iniected weakened pathogens

43.

LIST I

SreptecocCus preumoniae D.

Plasmodium vivax

Choose the correct answer from the options given below:

Active immunity

(2) Passive immunity (3) Non-specific

(4)

LIST II Common Cold Typhoid Malaria IV Pneumonia

A.Salmonella phi B. Rhmo viruse

Immunity provided to the foetus from the mother through placenta during pregnancy is: 1 (1)

44.

Match List Iwith List II

injecting inactivated pathogens

(2)

Choose the correct answer from the options given below: (1) A and D only (2) A and B only (3) Cand D only (4) Band C only

40.

Which of the following is passive immunisation?

23

immunityk

Innate immunity

Production of antibodies against antigens in the body is : (1) Innate immunity (2) Passive immunity (3) Active immunity (4) Non-Specific immunity

45. Match List I with List II LIST II

LIST I

A-II, B-IV, C-I, D-III (2) A-I, B-IV, C-II, D-I

A.

Physical Barrier

I

Saliva

B.

Cellular Barrier

II.

Interferons

(3)

A-I, B-I, C-IV,D-II

C.

Physiological Barner

III.

Skin

(4)

A-I, B-II, C-III, D-IV

D.

Cytokine Barrier

IV.

(1)

Read the passage and answer the question given below.

Malaria is caused by the Plasmodium parasite. The parasite is spread to humans through the bites of infected mosquitoes. When a host is exposed to or antigens, which may be in the form of living are dead microbes or other proteins,antibodies produced in the host body. This type of immunity is called active immunity. Active immunity is slow and takes time to give its full effective response. Injecting the microbes deliberately during immunisation or infectious organisms gaining access into body during natural infection induce active immunity, When antibodies are directly given to protect the body against foreign agents, it

is called passive immunity.

4L. Colostrum secreted by mother during initial stage of lactation provides passive immunity as it is rich in. (1)

Placental lactogen

(3)

Antigen

(2).

Prolactin (4) IgAantibodies

Polymorpho-nucear leukocytes

Choose the correct answer fromn the options given below: (1)

A-III, B-I, C-II, D-IV

(2)

A-II, B-IV, C-1, D-II

(3)

A-I, B-IV, C-II, D-II

(4)

A-IV, B-I,

C-II, D-II

Observe the diagram and answer the question given below. Heat

Heat)

dea

OSWAAL O CUET

16 Which of the following constitutes the first trophic level?

material at a particular (1) Standing crop

(1) Plarnts

(3)

y

46.

(3)

4/.

(2)

CarnivorestA

y

Herbivores

(4)

Omnivores()

49.

Sparrow comes under which of the following (1)

(3)

consumersia02

(3)

e

consumersLO

Secondary consumers

(2) Tertiary

Which

() 24 E

Each trophic level has a certain mass of living

:

(4) Time crop

among the following is not a primary

(1) Snake

Producersishigut

(2) Primary

Standing life

called as (2) Living crop

timne

consuner?

ocategories:

43.

(UG) Chapterwise Question Bank BIOLOGY

50.

Zooplankton

(2) Grasshopper Ci (4) Caterpillar

Which of the following is a part of detritus food chain?

Earthworm (3) Man (1)

r

(2)

Birds

(4)

Snake

UNITI: Reproduction Study Time

CHAPTER

Max. Time: 15 Hours Max. Questions: 50

1

REPRODUCTION IN ORGANISMS

Revision Notes Reproduction is biological process of formation of new offsprings from pre-existing organisms. ensures continuity > Reproduction of species generation after generation. Life Span is the period from birth to natural death of an organism. Mitosis is a type of celldivision, in which the nucleus divides into two daughter nuclei, cach containing the same number of chromosomes as the parent nucleus. > Sex cells or gametes are mature haploid male or female germ cell, produced by gametogenesis. > These gamete celis fuse during fertilisation and lead to formation of a zygote that develops into a new individual.

>

Juvenility represents the stage when organism develops the capacity to reproduce. Progressive deterioration in body of a living being is called ageing.

The terminal irreversible stage of ageing is knovwn as senescence. Mayfly lives for only one day wvhile giant tortoise lives for about 100-150 years and considered as the longest living animal on the Earth. Based on whether there is one or two organisms taking part in the process of reproduction the process

can be divided into two types-A sexuali and Sexual Production. Scan to know more about thís topic

Asexual Reproduction and Sezual Reproduction > When the offspring is produced by single parents with or without the involvement of gamete formation, Seznal and the reproduction is called asexual Aseual reproduction. Reproduction When two parents (opposite sex) participates in reproduction process and also involves the fusion of male and female gametes, it is called sexual reproduction Clones: Offsprings produced are genetically and morphologically similar to each other and to the parent, i.e. they are clones. Binary fission in this method ofasexual reproduction. a cell divides into two halves and rapidly grows into an adult. Ex. amoeba, paramecium. Budding small buds are produced that remain attached initially with parents and get separated on maturation. e.g., Yeast. Fungiand simple plants like algae reproduce thrvugh special reproductive structures like zoospores (motile structure), conidia (penicillium). buds (kyeàa) and gemmules (sponges).

Nucleus divides itself and forms daughter nuclei

-Daughter yeast

Nucleus.

-Parent Veast

Vacuole

Mouth

Fig l

Oswaal CUET (UG) Chapterwise Question

Bank

Human's.

Fertilization

transfer

Fertilization

Pi

External

ViviparoOus

Gametogernesis

intoa

the

Internal

inside develops

e.g.,

Gamete

Basis

Animals on the ment ofEmbryo Vpes

Embryogenesis

one

body,

e

Zygote

Zygote young female

Develop

off

The

Ovoviviparous

Fertilization

Oviparous

means hatched parent.

Events

Birds.

Events Plants fertilized/

e.g.,

Pre-tertilization

Fertilization

by are the

In

body

which develops Reproduction

the

seed,

unfertilized

the

the

within

e.g,

thick ovary

the ovules The into

the

eggs

into into

Animals

Snake.

Producing

embryo,

zygote

lay

fruit pericarp

Post

Sexual

eggs

of

young

of a

the

with

Orgarn

Sms

uctonin

Penicillium

Porded

Reproduction

Example,

sexual

Level

Sponge Third

Example,

Meaning

A

Map Level

Mind

SIsuaoue

Molds

Fissior

Zoospore Budding

by Reproduction

Trace Level

develops

A

by two

First

adult

Binary

spores

Second

the

Unfertilized

uogentoIdy

Regeneration

e.g,

egg an into

species

buds

Offset

:,Colocasia

Jasmine

and Amoeba.

into nucleus

organisms

:,Oxalis

portion

daughter

has lost

bud

Leaf Rhizome

Chlamydomonas

of

characteristic

: hyacinth

continuation

e.g.,

cell

of of Division

which

a

or

division

Eyes

from

Flatworm.

Onion

Stem:

Stem Stem

all

injured

of

cytoplasm

of

Bulbil

Bryophyllum:-

body

Ginger

Potato

individual

Formation

Renewal

:

: Yeast.

: Agave

•Runner Centella

Corms

Water •Bulb:

of

•Stolon Crocus

feature

a

a

of

been e.g.,

e.g.,

e.g.

is •

•

•

•

•

It

for

BEPRODUCTION IN ORGANISMS

3

Daugtter cells

Nudeus Nucleus diides Cytoplam divsdes

Eagmentation is also a kind of asexual reproduction Fig 2 in which an multiccllular organism splits into fragments. Ex. Spirogvra In plants, vegetative reproduction occurs by vegetative propagules like runner, rhizome, sucker, tuber, offset and bulb.

A sexual reproduction is the most common method of reproduction in organisms having simpler body like in algac and fungi but during unfavourable condition they shift to sexual reproduction. Vegetative propagation is a type of process in which new plants are obtained without the production of sexual structures i.c., seeds or spores. Different vegetative parts of plants are mentioned below.

Runner- oxalis Sucker- Mint and chrysanthemum Tuber- potato

Ofset- water hyacinth, pistia Bulb- onion, garlic Rhizome- ginger

Bulbil- aguve Leaf buds- bryophyllum

> Artificial Methods: In this type of method, only a small part of the plant organ is utilized for obtaining a new complete plant. Amongst them, the most common methods which are used are cutting, layering, and grafting. > Cutting: In cutting, a small piece of root is cut and when planted in moist soil, it will lead to the artificial inducement and development of adventitious roots. For examplelemon. > Layering: This method is used for growing rose, lemon, grape, hibiscus, and jasmine. The lower branches of these plants are bent a little bit and covered with soil in such a way that the tip of the branch protrudes from the ground and the middle part of the plant is inside the soil.

is carricd out Scan to kaow more about are on plants that having difficulty this topic or that generally in forming roots have a weak root system. Gametes arc specialised cells in sexual reproduction. They contain What is Grafting? half of the maximum number of chromosomes of the species and fuse with another gamete to give birth to an organism with double number of chromosomes of the gametic cells. A meiocyte is a type of cell that differentiates into a gamete through the process of meiosis. Through meiosis, the diploid meiocyte divides into four genetically different haploid gametes. The time of the meiosis through the meiotic cell cycle varies between different groups of organisms. Sexual dimorphism is the differences in appearance between males and females of the same species. Such as colour, shape, size and structure that are caused by inheritance of one or the other sexual pattern in the genetic material. the Animal dioecy is called gonochory where separation of sexes in different individuals can be observed. Hydra is a dioecious animal in which an individual produces either sperms or eggs. > Juvenile phase is also called vegetative phase in plant. In angiosperms, end of vegetative stage finishes when they begin to flower. In fowering plants, both male and female gametes are non-motile. In this case, the non-motile male gametes are transferred to the non-motile female gametes with the help of pollen tube in a process called siphonogamy. Self-pollination occurs when pollen grains are transferred from anther to stigma of the same flower. Cross-pollination allows the transfer of pollen grains from anther of the flower into stigma of another flower.

Grafting: Grafting

Cutting Cut Rooting

hormone Isolated cells Excised piece of leaf

Fig 3

A

Tissue culture

Oswaal CUET (UG)

4 transfer of pollen grains from the stigma is called pollination. The

Chapterwise Question Bank

BIOLOGI

Cross-pollination results in increase in genetic diversity as different plants combine their geneti information to produce new offspring.

anther. to the

QUESTIONS TYPE OBJECTIVE External fertilisation is a rule during sexual reproducti Choose the correct statements from the options below (b) (i) and (ii) (a) (i) and (iv) (i) and (iv) (d) (iii) and (ii) (c) a few statements related to extemal Given below are 7. [NCERT Exemplar, Q.7, Pg. 21] A fertilisation. gametes are formed and releasel and female male nThe simultaneously. the medium. are i) Only a few gametes areleased into exhibitina organisms the medium in majority of i) Water is fertilisation. external h2ve i) Offsprings formed as a result of external fertilisation an inside formed those better chances of survival than organism. options. Choose the correct statements from the given and (ii) (b) () (a) (iii) and (iv) (d) (i) and (iv) (c) (ii) and (iv) a post-fertilisation event in is following the 8. Which of [NCERT Exemplar, Q. 17, Pg. 4] flowering plants? grains (a) Transfer of pollen (b) Embryo development (c) Formation of flower (c) Formation of pollen grains a type of sexual 9. A multicellular, filamentous alga exhibits occurs after the division which the meiotic life cycle this alga has filament of adult zygote. The formation of [NCERT Exemplar, Q. 5, Pg. 2] diploid gametangia. and cells (a) haploid vegetative gametangia. diploid and cells vegetative (b) diploid gametangia. (c) diploid vegetative cells and haploid gametangia. haploid and cells (d) haploid vegetative amongst the following. statement from 10. Choose the correct Q. 13, Pg. 3] Exemplar, [NCERT iw)

lA|

MUTIPLE CHOICE QUESTIONS: features ofreproduction

Alew statements i)

describing certain

are given below. Gametic fusion takes place.

material takes place.

ii) Transfer of genetic place. iii) Reduction division takes

some iv) Progeny have

resemblance with parents.

NCERT Exemplar, Q.

1,

Pg. 1]

sexual both asexual and that are true for below. options the Sclect options given reproduction from the ii and ii (b) (a) iand ii i andii (d) The types of reproduction. (c) ii and iy types of various are on: 2. There an organism depend reproduction adopted by 15, Pg. 4] [NCERT Exemplar, Q. morphology of the organism. (a) the habitat and organism. (b) morphology of the of the organism. physiology (©) morphology and genetic make-up. habitat, physiology and formed by (d) the organism's offspring to applied term 'clone' cannot be The 3. because 1] sexual reproduction [NCERT Exemplar,Q. 2, Pg. DNA. possess exact copies of parental on to the (a) ofl'springs do not one parent is copiced and passed

(b) DNA of only offspring. are formed at different times. (c) ofl'springs offspring is completely different. (a) DNA of parent and statements support the view that 4. Which of the following process appeared much later elaborates sexual reproductive evolution. in the organic (NCERT Exemplar, Q. 13, Pg. 3] simpler body design. Lower groups of organisms have groups. common in i) Asexual reproduction is common lower groups of in higher iii) Asexual reproduction is

organisns.

in angiosperms iv) The high incidence of sexual reproduction and vertebrates. below. Choose the correct answer from the options given i, ii and iv (b) ii and i, (a) ii (d) ii, ii and iv (c) i, ii and iv 5.

(a) (b) (c)

more Offsprings formed by sexual reproduction exhibit variations than those formed by asexual reproduction because [NCERT Exemplar, Q. 12, Pg. 3] sexual reproduction is a lengthy process. gametes of parents have qualitatively different genetic compositions. genetic material comes from parents of two different species. greater amount of DNA is involved in sexual reproduction.

I

(d) 6. A few statements with regard to sexual reproduction are given below. [NCERT Exemplar, Q. 4, Pg. 1]A i) Sexual reproduction does not always require two individuals.

i) Sexual reproduction generally involves gametic fusion. iii) Meiosis never occurs during sexual reproduction.

(a) Dioecious (hermaphrodite) organisms

are seen only in animals.

seen only in plants. (b) Dioecious organisms are seen are in both plants and animals. (c) Dioecious organisms seen are only in vertebrates. (d) Dioecious organisms 12 chromosomes 11. The male gametes of rice plant have in the female number in their nucleus. The chromosome will be seedling the cells of the and zygote gamete, Q. 6, Pg. 2] [NCERTExemplar, respectively (b) 24, 12, 12. (a) 12, 24, 12. (d) 24, 12, 24. (c) 12, 24, 24. certain features that describe statements below given 12. The are observed in the pístil of flowers.

i) i) iii) iv)

(a) (c)

Pistil may have many carpels. Each carpel may have more than one ovule. Each carpel has only one ovule. Pistils have only one carpel. Choose the statements that are true from the options (b) (i) and (ii) (1) and (i) (d) (ii) and (iv) (ii) and (iv)

below.

REPRODUCTION IN ORGANISMS

5

Which of the following situations correctly describe the imilarity between an angiosperm egg and a human cgg? are formed only once in a Eggs of both ) lifetime. in Both the angioSpem cg8 and human egg are BRoth the angiosperm cgg and human eggstationary. are motile 13.

transported. Syngamy in both results in the fomation zygote. of Choose the corrcct answcr from the options given below. (a) (ii) and (iv) (b) (iv) only (c) (iii) and (iv) (d)

a

(i) and (iv) number of chromosomes in the shoot tip cells of maize plant is 20. The number of chromosomes in the microspore mother cells of the same plant shall be (b) 10. (a) 20. (c) 40. (d) 15. 16. There is no natural death in single-celled organisms, like Amoeba and bacteria, because (a) they cannot reproduce sexually. (b) they reproduce by binary fission. a narental body is distributed amongst the offsprings.

What will Z1.A protozoan reproduces by binary fission. be the number of protozoans in its population after six generations? (b) 24 (a) 128 (d) 32t1 (c) 64 22. Which of the following is not truc (a) Water Hyacinth growing in standing water drains oxygen from water that leads to death of fishes. produced by asexual reproduction are called Ofisprings (b)

The

(d) they are microscopic. 16. Amoeba and Yeast reproduce asexually by fission and

budding respectively, because they are (a) microscopic organisms. (b) heterotrophic organisms. (c) unicellular organisms. (d) uninucleate organisms. 17. Appearance of vegetative propagules from the nodes of plants, such as sugarcane and ginger, are mainly because A1 (2) nodes are shorter than internodes. (b) nodes have meristematic cells. (c) nodes are located near the soil. (d) nodes have non-photosynthetic cells. 18. Identify the incorrect statement. (a) In asexual reproduction, the offsprings produced are morphologically and genetically identical to the parent. (b) Zoospores are sexual reproductive structures. (c) In asexual reproduction, a single parent produces ofspring with or without the formation of gametes. (d) Conidia are asexual structures in Penicillium. 19. Match the organisms given in Column A with the vegetative propagules given in Column B.

A. Bryophyllum

Column B (Vegetative propagules) i) Offset

B.

iü)

Eyes

iii))

Leaf buds

ColumnA (Organisms) Agave C. Potato D. Water hyacinth

iv) Bulbils

D. (iv) (a) A. (ii) C. (i) B. (iii) D. (i) (b) A. (iii) C. (ii) B. (iv) (ii) D. (c) A. (iv) C. (iii) B. (i) D. (i) (d) A. (iii) B. (i) C. (iv) 20. Which one of the following is correctly matched?

(C)

clone. Microscopic, motile asexual reproductive structurc called ZOospore.

Banana and ginger the plants arise from (d) In potato internode present in the modified stem. 23. Planaria possesses high capacity of (a) Regeneration (b) Alternation of generation (c) Bioluminescence (d) Metamorphosis 24. Which of the following is not a vegetation propaganda?

Runner of grass Offset of water hyacinth Rhizome of Ginger Bud of Hydra 25. Flagellated, motile asexual reproductive structure are called : (a) Megaspores (b) Aplanospores (d) Microspores. (c) Zoospores 26. Which of the following flowers only once in the life time (b) Bamboo species (a) Mango (d) Jackfruit (c) Papaya 27. Which of the following statement is true of date palm? (a) It is monoecious producing both staminate and pistillate flowers in the same plant. (b) It is monoecious producing staminate flower in one and pistillate flower on the another tree (c) It is dioecious producing staminate flower in one and pistillate flower on the another tree (d) None of these 28. The first organisms were (b) eukaryotes. (a) autotrophs. (d) chemo-heterotrophs (c) chemoautotrophs. 29. Which one of the following part of the plant when put into the soil is likely to produce new ofspring? a) part of an internode (b) a stem cutting with a node (c) part of a primary root (d) a flower 30. In sporulation Amoeba undergoes:. (b) Multiple fission (a) Binary fission (d) None of these (c) Encystation (a) (b) (c) (d)

(a) Chlamydomonas-Conidia

[BASSERTION &REASON

(b) Yeast-Zoospores (c) Onion-Bulb

Directions: In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct

(@) Ginger-Sucker

choice as:

Oswaal CUET (UG) Chapterwise Question

6 reason (R) are trnue and reason (R) () Both assertion (A) and the correct explanation of assertion (A).

1.

is

either of the parents. Assertion: Several

seed

bearing

plants

2. 3. 4.

propagate

vegetatively. propagation Reason: Sweet potatoes undergo vegetative by means of root tubers. that gives a vital link 4. Assertion: Zygote is the only cell an organisms. between two generation of a Reason: The two gamete fuse to form single zygote. a 5. Assertion: Papaya is dioecious plant. sex organ are born on same female and Male Reason: plant. Assertion The life span plant is long then the animals. to divide Reason: Plant have meristematic tissuc continuously through their lifc. of 7. Assertion: Asexual reproduction involves formation an clones of organism. Reason: Clones are morphologically and genetically identical. corns ctc. 8. Assertion: Plant structure such as tubers, bulbs, have asexually reproducing method. Reason: They are common means of propagation in most of the monocot families. 9. Assertion: A plant can be retaincd and multiplied indefinitely without any change variation through asexual reproduction. Reason: Asexual reproduction does not involve meiosis and syngamy. , 10. Assertion: Sponges are simple cellular level and less specialize organisms. Reason: Sponges shows high power of regeneration. 6.

:

[C| COMPETENCYICASE-BASED QUESTIONS: I. Read the passage carefully and answer the question given after the passage from 1-5. Organisms like fungi, plants and animals shows diversity. They differ greatly in external as well as internal structures,organisations, their anatomy and physiology. Inspite of that they lived together and have almost similar pattern of reproduction. They have different life forms. life span and individuality. There are different types of reproduction to produce new organisms, like asexual reproduction (in which only one parent is involved to produce offspring), and sexual reproduction (in which two different parents with different genetic compositions are involved). Due to living in large biological diversities, each organism undergoes different mechanisms to reproduce

LIfe Span A. 20-25 years B. 140 ycars C. 60 ycars

lifespan

Banyan tree Cow Parrot Crocodile D. 25 ycars C 1-D, 42-A, 3-B, (a) (b) 1-B 2-A, 3-D, 4-C (c) 1-D, 2-A, 3-C, 4- B (d) 1-D, 2-C, 3-A,4- B 2. Which of the following an is cxample of perennial nl (a) Pea (b) Watermelon (c) Banana (d) nonc of these 3. Vegetative phase of plant is also called. (a) juvenile phase (b) reproductive phasc (c) Sencscent phase (d) none of these 4. Which of the following statement is false (n) Hydra reproduces through regeneration (b) tuber and corm formation are the mcthod of asezual reproduction (c) Spirogyra reproduce through budding (d) spores in unfavorable condition form cyst around them 5. The asexually reproduced organisms arc (a) genctically identical (b) morphologically identical (c) a single parent involved 1.

of

3.

Arrange the following in animals with their

Animal name

reason (R) are true but reason (R) is (2) Both assertion (A) and assertion (A). not the correct explanation reason (R) is false. (3) Assertion (A) is true but reason (R) is true. (4) Assertion (A) is false but emerge from the buds (cye) of 1. Assertion: Small plantlet etc,: the site of origin of potato tubers, rhizome of ginger node. the these plantlets, is invariably cells, which hclp in Reason: The nodes contain metameric their vegetative propagation. from a cross between two 2. Assertion (A): Hybrids result genetically unlike parents. superiority of hybrid over Reason (R): Hybrid vigour is the

Bank

(d) all of these

II. Study the following diagram and answer the given below 6-10.

question

Which type of reproductive bodies seen in the given diagram? (b) conidia formation (a) Cyst (d) regeneration (c) budding I 7. Match the sexual reproductive structure in Column with correct the II and select Column in given the organism 6.

option

Column I(reproductive structure) Column II (Organism) Chlamydomonas (1) A. Conidia Hydra B. Gemmules (2) Penicillium (3) C. Zoospores Sponges D. Buds (4) Banana (5) D-1 (b) A-4, B-3. C2, (a) A-3, B-4, C-1, D-2 D-I (d) A-3, B-4, C5, (c) A-2, B-4, C4, D-2 not a method of asexual is following 8. One of the reproduction

(a) Cutting (c) Budding

:

(b) Grafting (d) Conjugation.

PEPRODUCTION IN ORGANISMS

7

Renroduction occurs through conidia (a)

(c)

Aaramecium

in-ws

10. Asexual reproductive structures of sponge is : (b) (a) Genmules (d) None of these (c) Bulb

(b) Plasmodium (d) Penicillium

Amoea

Conidiae

ANSWERKEY [A]MULTIPLE CHOICE QUESTIONS

1.()

2. (d)

3.

11.(©)

12. (a)

13. (b)

14. (a)

21. (c)

22 (d)

23. (a)

15.(c)

16. (c)

24. (d)

25.(c)

26. (b)

1.(a)

2. (b)

3. (b)

1. (b)

2. (c)

3. (a)

(a)4.

(c)

5. (b)

8. (b)

9. ()

17. (b)

18. (b)

19. (b)

20. (c)

27, (c)

28. (d)

29. (b)

30. (c)

7. (6)

6. (b)

B] ASSERTION& REASON 7. (b)8. 5. (c) (a) 6. (a) IC| COMPETENCY/CASE-BASED QUESTIONS 4. (a)

4. (c)

|5.

(d)86.

(b)

7.(A)8.

(d)

10. (c)

9.(a)

10. (b)

9. (d)

10. (a)

ANSWERS WITH EXPLANATION [AJ MULTIPLE CHOICE QUESTION: 1. Option (c) is correct Explanation: In both types of reproduction,transfer genetic of materials takes place from one generation to another and also progeny have some resemblance with their parents, Gametic fusion (fertilisation of sperm and ovum to form zygote) and reduction division (also called meiosis) are present only in sexual mode of reproduction. 2. Option (d) is correct Explanation: There are different types of reproduction to produce new organisms, like asexual reproduction (in which only one parent is involved to produce offspring), and sexual reproduction (in which two different parents with different genetic compositions are involved). Due to living in large biological diversities, each organisn undergoes different mechanisms to reproduce. They all depend on their habitat, physiological properties, genetic constitution and other factors to reproduce and produce new organism. 3. Option (a) is

correct

Explanation: Clone cannot be applied to offsprings produced from sexual reproduction because sexual reproduction involves the fusion of male and female gametes from two parents. Therefore, the offsprings produced from them are not identical to the parents. This genetic recombination leads to variations which play an important role in evolution. Whereas offsprings produced as a result of asexual reproduction are identical to cach other, both physically as well as genetically. They are the exact copies of their parents. Hence, they are called clones. 4. Option (c) is correct Explanation: Statements (i), (ii) and (iv) support the view that elaborates sexual reproductive process, appeared much later in the organic evolution. Asexual reproduction is not common in higher group of organisms. It is common amongst single-celled organisms, and also in plants and animals with relatively simple organisations. 5. Option (b) is

correct

Explanation: More complex offsprings are formed by sexual reproduction as compared to asexual reproduction. Offisprings produced by sexual reproduction exhibit more variation than those formed by asexual reproduction because gametes of parents have qualitatively different genetic compositions. Due to he genetic variations, individuals within a population have slight diterences. In case of asexual reproduction, due to involvement OL Only one parent there is no chance of genetic variations.

Option (b) is correct Explanation: Sexual reproduction involves both male and female gametes (cither from same or different parents) and its fusion results in the formation of new organisms. Meiosis (reduction division) takes place during sexual reproduction to produce haploid gametes. It is important to keep the number of chromnosomes in species constant. In sexual reproduction, fertilisation occurs externally as well as internally. 7.Option (b) is correct Explanation: External fertilisation occurs outside the female body, usually in water. It takes place in most aquatic organisms, such as a majority of algae and fishes as well as amphibians. During external fertilisation, organisms release large number of gametes the surrounding medium to increase the chances of syngamy. A major disadvantage is that the offsprings are extremely vulnerable to predators threatening their survival up to adulthood. 6.

8.

Option (b) is correct

Explanation: During the sexual reproduction, the events which take place after the formation of zygotec are called post fertilisation events. The process of embryo development from the ygote (called embryogenesis) takes place after the fertilisation. In all flowering plants, the zygote is formed inside the ovule. In ovule, the zygote divides several times to form an embryo. 9. Option (d) is correct Explanation: Adult filament of multicellular alga have haplontic life cycle in which the meiotic division occurs after the formation of zygote. So, the filament of this alga has haploid vegetative cells and haploid gametangia. A multicellular gametophyte or gametangia which is haploid (n) alternates witha multicellular sporophyte which is diploid (2n). A mature sporophyte produces spores (haploid cells) by meiosis, a process which reduces the number of chromosomes to half, from 2n to n. 10. Option (c) is correct Explanation: Dioecious organisms are those organisms which have male and female reproductive organs in different individuals. These organisms are seen in both plants and animals. In dioecious angiosperms, male and female parts are found in separate flowers e.g. Mulberry. Hence, dioecious plants bear sexual dimorphism. Most animals are dioccious. Insects, spiders, fish, amphibians, reptilians, birds and mammals exhibit sexual dimorphism.

Oswaal CUET(UG)

Option (c) is correct Explanation: In fenale gamete, the chromosome number will 11.

zygote is a fertilised be same as that of the male gamete (12). A eggseed which means gametes from the parents have been be Combined (diploid) and thus. the chromosome number will out develops young a plant. Sporophyte 24 (2n). A seedling is number Irom a plant embryo from a seed. So, the chromosome further will which (2n), 24 be in the cells of the seedlings will new individual. to diploid give rise

Female gamete (n) = 12 Zygote (2n) = 24 Cells of seedling (2n)= 24 12. Option (a) is correct Explanation: (a) Pistil (gynoecium) of a flower.

is the female reproductive part It is centrally located and consists

potential seeds of ovary (a swollen base), which contains the ovary; and a pollen the or ovules; style (a stalk), arising from to a ovary attached is it Inside receptive tip, the stigma. or in parenchymatous cushion called placenta, either singly cluster. 13. Option (b) is correct Explanation: Both angiosperms and humans exhibit internal fertilisation and remain reproductively active throughout egg their reproductive phase. It means that the formation of a many once, time. life in times but also takes place not only In humans, egg released from the ovary reaches the Fallopian tube (for fertilisation) and from there to uterus for implantation. So, the egg is considered as motile not stationary. Similarly, in flowering plants (angiosperms), the gametes are non-motile cells within gametophytes, but for the fusion to take place the non-motile male gametes are carried to female gamete by pollen tubes. 14. Option (a) is correct Explanation: The whole plant body of maize plant including shoot tip cells remains in diploid (2n) condition. As the microspore mother cell is a part of reproductive organ, the chromosome number in these cells will remain same as the individual, that is, 2n = 20. These microspore mother cells are further responsible for producing male gametes, that is, haploid (n) by reduction division. 15. Option (c) is correct Explanation: There is no natural death in single-celled organisms, like Amoeba and bacteria, because parental body is distributed amongst the offsprings. In Amoeba and bacteria, the parental body itself divides into two parts and becomes daughter cells, Then, each of these daughter cells rapidly grow into adult organisms. Therefore, the parent organism cannot be said to have died, it continues living as daughter cells. 16. Option (c) ís correct Explanation: Asexual reproduction is common in unicellular organisms due to their simple cell organisation. carry out all of their life processes as one These organisms single cell, All prokaryotes, fungi and protists (e.g., Amoeba, etc.) are unicellular organisms. Fission and buddingare types of asexual reproduction in which a single parent will reproduce new organisms. Amoeba and Yeast reproduce by fission (binary fission) and budding respectively. In binary fission, parent cell divides into two equal halves (called daughter cells). Daughter cells are identical to each other and to their parent cell, for example, Amocba, Euglena and bacteria. In budding, a new organism is

Chapterwise Question

Bank

eioLOG

formed from a small part (called as bud) ) of theparent'sboty Then this bud detaches from the parent body and develops a new organism, for example, Hydra and Yeast. it 17. Option (b) is correct Explanation: Appearance of vegetative propagules from nodes of plants, Such as sugarcane and ginger, are mai because of the presence of meristematic cell in nodes Meristematic cells are responsible to control the growth a development of tissues and organs in plants. Nodes (orese the modified stems) when come in contact with damp soil water. they produce roots and gives rise to new plants 18. Option (b) is correct Explanation: Zoospores are microscopic motile asersl reproductive structures. They are produced by certain algze some fungi. They move with the help flagella. Other comm asexual reproductive structures are conidia (penicillium), bude (Hydra) and gemmules (sponge). 19. Option (b) is correct The correct matches of the vegetative propagules are given below: Column B(Vegetative S. No. Column A(Organisms) propagules) Bryophyllum ii) Leaf buds A. Agave iv) Bulbils Potato C. i) Eyes i) Offset hyacinth Water D. B

Column A (Organisms)

Column B (Vegetative propagules)

A. Bryophyllum B. Agave

iv) Bulbils

C. Potato

i)

D.

Water hyacinth

ii)

Leaf buds Eyes Offset

20. Option (c) is correct

Explanation: The bulbs are underground condensed shoots which have one or more buds that give rise to new plants. Onion is vegetatively propagated by bulbs. 21. Option (c) is correct Explanation : Binary fission is a mode of asexual reproduction in protozoan through which it produces two offsprings from parent individual. So, In lst generation : there are 2 protozoans. In 2nd generation: there are 2 x 2 = 4 protozoans In 3rd generation : there are 4 x 2= 8 protozoans In 4th generation : there are total 16 protozoans. In 5th generation : there are total 32 protozoans In 6th generation : there are 64 protozoans. Thus, the population of protozoan will be 64, after six generations.

22. Option (d) is correct Explanation: In potato, Banana and ginger new plantlets arse from nodes of the modified stem not from internode. 23.Option (a) is correct Explanation: Planaria is an organism which shows higi or capacity of regeneration in which the cutted part damageu part form again. 24. Option (d) is correct Explanation: Considering the misprinted words vegetatiou propagau propaganda as vegetative propagules. Vegetative a process planb which in is a form of asexual reproduction. It is reproduce from stem, roots and leaves.

JPEPRODUCTION IN ORGANISMS

the units vegetative propagation arc runner, rhizome, sucker, tuber, oflset, bulb etc. as they are to new offspring. Buds in Hydra are capablc of giving rise asexual reproductive structures, of

In plants,

25. Option (c) is

correct,

Ernlanation: Zoospore 1s a motile, a sexual spore, which uses its flagella for locomotion. Exanmple : Euglena. 26. Option (b) is

correct

Crnlanation: Bamboo species have a life cycle of about 80 100 vears and generally flowers only once in its lifctime. So, the correct answer is optionb. 27.Option (c) is correct Explanation: Date palm is dioccious producing staminate (male) flowers in one tree and pistillate (female) flowers in another tree.

Option (d) is correct Explanation: The first living beings were single-celled nrokaryotes, like bacteria. These living beings were present in the environment of soupy sea having abundant organic molecules. Nutritionally, they were chemo-heterotrophs. 28.

Option (b) is correct Explanation: The plant when put into the soil is likely to produce new offspring by a stem cutting with a node, this type of propagation is called layering. 29.

Option (c) is correct Explanation: In sporulation Amoeba undergoes encystation due to unfavorable condition around them, whenever it get favorable condition it comes out from this condition and 30.

germinate. B] 1.

9 6. Option (a) is correct Explanativn: Animnal body have limitcd body growth while plant have meristematic tissue at the tip which has division

capacity throughout life.

s

7. Option (b) correct. as asexual Explanation: (b) The reproduction is known reproduction, when an offspring is produced by a single parent a result, the without the involvement of gamete formation, As are offspring that are produccd are not only similar to onc another but a group of morphologically also exact copies of their parent. Such and genetically similar individuals are called clones. 8. Option (a) is correct Explanation: (a) Asexual reproduction produces individuals that are genctically identical to the parent plant. Roots such as corms, stem tubers, rhizomes, and stolon undergo vegetative reproduction. They are usually found in monocotylcdonous families.

S9.

Option (a) is correct Explanation: (a) In asexual mode of reproduction, the genetic

constituent remains the same. So the off'spring and parents are morphologically and genetically same. 10. Option (b) is correct Explanation: Sponges are non-motile animals attached to some solid support. The body design involves very minimal differentiation and division into tissues.

[CjcoMPETENCYICASE-BASED QUESTIONS: 1. Option

(b) is correct

Explanation: Animal name 1.

Banyan tree

Life Span A. 140 years

ASSERTION & REASON:

2. Cow

B. 20-25 ycars

Option (a) is correct

3. Parrot

C. 25 years D. 60 years

Explanation: Small plantlet emerge from the buds (eye) of potato tubers, rhizome of ginger etc,: the site of origin of these plantlets, is invariably the node which contain metameric (dividing cells) cells, which help in their vegetative propagation 2. Option (b) is

correct.

Explanation: Hybrid vigour is superior in characteristic such as size, growth rate, fertility, etc., of a hybrid organism over it's parents. Hybrid, on the other hand is a result of cross between parents of two different types. 3. Option (b) is

correct

Explanation: Fomation of new plants by means of vegetative units as tubers, buds,, rhizomes is called vegetative propagation. It is useful for producing large number of offsprings within a short time and for preserving qualities such as disease resistance. In sweet potato, root tubers take part in vegetative

correct

Explanation: Zygote forms after fusion of two gamete (male and female). It ensure the characteristics of both the parents. 5. Option (c) is

2. Option (c) is correct , Explanation: Perennial plants grow again and again have years. can more shorter blooming period. They live for two or an are So, Banana is annual example of perennial plant rest two

plants.

3. Option (a) is correct Explanation: Juvenile phase is the phase of plant from birth to reproductive maturity, this phase shows full development of the plant body, hence also called vegetative phase. 4. Option (c) is correct

Explanation: Spirogyra is type of algae which reproduces through fragmentation. 5. Option (d) is correct

Explanation: The asexually reproduced organisms are

propagation. 4. Option (a) is

4. Crocodile

correct

Explanation: Papaya is dioecious plant as it has male and emale reproductive part in different plants,

genetically identical, morphologically identical and only single parent involved, hence all are correct. 6. Option (b) is correct.

Explanation: Conidium or conidia is an asexual reproductive bodies found in fungi which is situated at the extreme side of the top of the hyphae.

Oswaal CUET (UG) Chaptervise Question Bank BIOLOG

10

of reproduction while conjugation is a sexual in which genctic material transter between bacterial celtmehr 9. Option (d) is correct Explanation: Paramecium , Amoeba and plasmodium While penicillium reproduce through fission. reprodu mcthod

correct Explanation: Column I (reproductive structure) Column II (Organism) 7.

OptionA is

A. Conidia

(1) Penicillium

B. Gemmules

C. Zoospores

(2) Sponges (3) Chlamydomonas

D. Buds

(4) Hydra

8. Option (d) is correct budding all are asexual Explanation: Cutting, grafting, and

through spores like conidia. 10. Option (a) ís correct Explanation: Gemmules are the internal buds wheneverthe attain maturity ,they detach from parental body and Survive z new invidual.

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CHAPTER

2

Revision Notes Flower Morphology

Max.

SEXUAL REPRODUCTION IN FLOWERINGPLANTS

Flowers are fascinating to biologists due morphological and to their intricate embryological features. The structure a of flower can be described parts, each with typical own specific in several its function in reproduction, an Here's overview of the main parts of a flower: 1. Receptacle: The receptacle which all the flOwer parts are is the tip of the stem to attached. It is the base or foundation of the flower. 2. Sepals: Sepals are are usually green, the outermost part of the flower and although can be colored some species. Sepals protect the they in flower during its bud stage. Collectively, the sepals are known as the calyx. 3. Petals: Petals are often brightly colored and are located just inside the sepals. They serve to attract pollinators like bees and butterflies. Collectively, the petals are known as the corolla. 4. Stamnens (Androecium):

Stamens are the male reproductive parts of the flower. Each stamen typically consists of two main parts: o Filament: This is a thin, elongated stalk that supports the anther. o Anther: The anther is the top part of the stamen, and it contains pollen sacs. Pollen grains are produced in these sacs. 5. Pistil (Gynoecium): The pistil is the female reproductive part of the flower, and it usually consists of three parts: O Stigma: The stigma is the sticky, often knob-like structure the top of the pistil. It serves as the landing platform for pollen. o Style: The style is a slender tube-like structure that connects the stigma to the ovary. o Ovary: The ovary is the swollen base of the pistil, and it contains the ovules. Once fertilization occurs, the ovary develops into a fruit. 6. Ovules: Ovules are tiny structures within the ovary that contain the female gametes (eggs). These are the structures that will eventually become seeds when

9. Floral Axis: The floral axis is the central axis of the flower, and it is where all the floral parts are attached. It extends from the receptacle to the tip of the floral bud. 10. Pedicel: The pedicel a is small stalk that connects the flower to the main stem of the plant. It's especially important when flowers are borne on stalks rather than directly on the main stem. These are the basic structural components of a flower. The arrangement and characteristics these parts can vary greatly of between different species plants, leading to the wide diversity of flowers seen in of nature. Each part plays a specific role in the flower's reproductive process, ensuring the plant's ability to produce seeds and propagate itself.

Pre-fertilization: Structures and Events o Prior to the visible appearance a of

flower, the plant undergoes hormonal and structural changes, leading to the development of the floral primordium. o Inflorescences are formed, bearing floral buds that eventually become flowers. o Within the flower, the male and female reproductive structures, the androecium (stamens) and the gynoecium (female reproductive parts), differentiate and develop. o The androecium comprises stamens representing the male reproductive organ, while the gynoecium represents the female reproductive organ.

Anther O A typical stamen consists

of two parts: the slender filament and the terminal bilobed structure known as the anther. o The anther's proximal end attaches to the thalamus or petal of the flower. o The number and length of stamens vary among different flower species.

Connective

Epidermis

fertilized. 7. Nectaries: Some fowers have nectaries, which are specialized structures that produce nectar. Nectar attracts pollinators by providing them with a food SOurce, O.

Pollen Grains: Pollen grains are produced in the anthers of the stamen. These tiny grains contain the male gametes (sperm cells) needed for fertilization.

Study Time

Time: 1:5Hours Max. Questions: 50

Endotheium Middle layers

Sporogenous tissue Tapetum

Fig 1: Transverse section of a young anther

ntegument htegument

sac

blengrains

Epldernis

Endothecdum

sac

layers

(OHTbyo

Epidermis

unnde

-Hilum

OBApetu

-Middie

embryo Chalaza

0uterIhner Hydrilla.

megasporangium,

Level

Microsporangium

NACarpels

Vallisneria,

grain

Endothecum

e.g.Daylilies

grasses;

Endothecu

-Thin

Self-incompatibility

positions.

Yucoa

porogenous

and

Connethe

MndMap

Epidermis

issue

pollen

anther

Signa

Stamen,

e.g.

e.g. e.g.

Stouum

and

Level

(Entomophily) Syncarpous

Thalamus

Nsgma

anther

Pistil,

different

(Anemophily)

(Ornithophily)

(Hydrophily)

Savt

of

Ovary

-Style

|Arrangement

the

unisexual

gametophyte

from

Tace

plant.

at from

from!

the

another

(Dicliny)

transfer

different

layers

of

gametophyte

Cemale

Production

of

promoting

pollen

stigma plant.

a

the

same

stigma

:

the

to

Male

flowers

•

of

pollen

pollen

-Filament

FHrst

•Birds

Stamen

pollination

Abiotic

Biotic

Xenogamy

Geitonogamy:

for

flower

Ma

Anther

of

•Insects

Water

Wind

transfer

transfer stigma

Middle

to the

Autogamny:

anther

Pre-fertilisation

the

anther

of

-Petal

same

-sepal

and

Devices

cross

to

lower

events

Level

stigma

the

receptivity synchronised.

release

Outbreeding

the

Devices

Pollen stigma Apparatus

Ovule

not

es Pollination Micropyle

Structure

Synergid/

bllentube

Alitorm

stigma involving

ecognition

pollen

dynamic

Flower

Stigma

Ovary

-

Reproduc eringo

Style

by

Pollen-pistil interaction

growth.

followed process

a

seed Pistil

pollen

is

fruit

tube

It

of and Significance

C

formation

dispersal dispersal

many

to

crop pollen modes

species Production

Degenerating

synergids

without

for

(2n)

Degenerating

endosperm

approaches

desired

Special

seed

Zygote

Double

by

antipodal

(3n)

(PEC)

mechanisms

Achieved

(PEN)

of

help

Hybridisation

cells

endosperm

fertilisation

Fertilisation

the areas

of

fertilisation

and

nucdeus

Events

Irimary

cell

using

Primary

pollination.

other

major

of

dispersal

oneseed

seeds

fusion

Parthenocarp

Hmasculation

Artificial (Non-endospermic)

Post-

by

Occurrence

in

have

colonise

Seed

than seeds.

in

embryo

fruits

fertilisation.

a

the

Non-albuminous

of

Development|

without

for

one

more

grains

+

fertilisation

of

Syngamy

Omauon

fruit

For

of

is

seeds

=Double

of Development

It

(Endospermic)

seed

endosperm

Albuminous

embryo

ovary

improvement

Tiple

lopmentofs

apex -Scutellum

Coleoptile

Eplat

formation. -Shoot

Mesocarp

of tnDevelopmet

than

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Seed

fruit

ovary

fruit

fue hue

other

e

10nocot

nutrition

embryo groundnut,

the

from Cotyledons

parts

to contribute

Hypocotyl

M eg.:Apple

develops

provides

Plumule

of

completely

growing

seed coconut.

Roct

LS.

When

pea, some

fruit Mango

It

to

e.g-

eg:

castor,

Consumed

in

When

seed

in

Persist

e.g

emb. en

cap Radice

Dicot

I REPRODUCTION IN FLOWERING

SEXUAL

PLANts

13

from various species exhibit significant ariations in size, shape, and anther attachment. Starmens

Microsporangium oA typical angiosperm

o The o

A

anther is bilobed, with eachlobe containing two microsporangia (dithecous). Microsporangia develop into pollen sacs, which are fled with pollen grains. A transverse section a of microsporangium reveals four wall layers: epidermis, cndothecium, middle layers, and tapctum.

o o

tapetum nourishes developing pollen grains and has dense cytoplasm with multiple nuclei. Sporogenous tissue in the microsporangium undergoes meiotic divisions to form microspore tetrads, with each tetrad containing potential pollen or microspore mother cells. This process ofmicrospore formation from apollen mother cel through meiosis is known as microsporogenesis. Microspores within each microsporangium cluster as tetrads and mature into individual pollen grains. Scan to know more about thís topie

Epidermis

Endothecium Middle layers Formation of

Mirospore

Male Gametes

mother cells

Tapetumoi

sVegetative

cell

Exine

-

Intine Generative cell

Fig 2: Enlarged view of an microsporangium

Fig 3: Structure of two-celled male gametophyte (pollen grain)

Meiosis I

9e4SMicrospore al

i3Fig

mother

Meiosis I

cells3ht

Microspore dyad 4:

Microspore tetrad

Microsporogenesis

Vacuoles

Vegetative Cell

Nucleus

Generative cell Asymmetric Spindle a pollen grain Fig 5: Stages of a microspore maturing into

Oswaal CUET (UG)

14 Pollen Grain o Pollen grains are the male

Scan to know more about this topic

tophytes. o They typically have a spherical shape with sizes ranging from 25 50 micrometers in diameter. Formation of structure The of a pollen grain consists of Pollen several layers, cach with distinct functions. These layers include: of I. Exine: The outermost laver the pollen grain is called a resistant layer primarily and It tough is the exine. made up of a substance called sporopollenin. The grain CXine protects the delicate contents of the pollen as and radiation UV Irom environmental factors, such support. structural It desiccation. also provides 2. Germ Pores: The exine often features small openings pores are essential for the called germ pores. These when it lands on the grain pollen germination of the or stigma of a flower. The sporopollenin layer is absent emergence pores, of allowing for the thinner around these the pollen tube. a 3. Intine: Beneath the exine, there is layer called the intine. is innermost layer of the pollen grain wall. The intine the It is much thinner than the exine and is composed mainly of cellulose and pectin. The intine is responsible for facilitating the growth of the pollen tube after pollination. It provides a path for the pollen tube to penetrate through toreach the ovule within the flower's ovary. 4. Cytoplasm: Inside the intine, there is a small amount of cytoplasm. This cytoplasm contains the two cells found in most mature pollen grains: o Vegetative Cell: This cell is larger and contains abundant food reserves. It also has a large, irregularly shaped nucleus. O

(syncarpous) or free (apocarpous).

AL

game

Generative Cell: The generative cell is smaller and floats within the cytoplasm of the vegetative cell. It contains dense cytoplasm and a nucleus. In many flowering plants, this cell undergoes mitosis to form

Chapterwise Question Bank BIOLOGN

o

Each pistil comprises three parts: stigma, Ovary.

style,

o The stigma serves as the landing platform for pol slal grains, the style is an elongated structure beneath Poli O

L

stigma, and the ovary has the ovarian cavity te (locule). The placenta inside the ovary gives ise megasporangia, also known as ovules.

The Megasporangium (Ovule) The ovule is attached to the placenta via o

the funicle.

o

The body hilum.

of

the

ovule

fuses

with

a

stalkcalled

the funicle

at the

Integuments protect the ovule andIencircleethenucellus, leaving a micropyle at the tip. o The chalaza represents the ovule's basal part. o Inside the ovule, the nucellus houses the embryo es or female gametophyte, generally formed from a sinol megaspore. o

Megasporogenesis o A megaspore mother

cell (MMC) undergoes meiotie division to produce four megaspores. o One of these megaspores becomes functional, while the others degenerate. o The functional megaspore develops into the female gametophyte (embryo sac) through a process known as monosporic development.

Female Gametophyte o The functional megaspore divides mitotically to form the 2-nucleate embryo sac.

o Subsequent mitotic divisions lead to the 4-nucleate and

then the 8-nucleate stages. Cell walls form after the 8-nucleate stage, organizing the typical 7-celled female gametophyte or embryo sac. two sperm cells before fertilization. o The embryo sac consists of cells at the micropylar end The unique structure of pollen grains, with their tough (egg apparatus), cells at the chalazal end (antipodals), exine,oo:M germ pores, and inner layers, allows them to withstand various a central cell with polar nuclei. and environmental challenges during pollination and fertilization. The pollen tube, whích grows from the germinating pollen O The egg apparatus includes synergids and an egg cell. grain, plays a critical role in delivering sperm cells to o The central cell contains polar nuclei. the female reproductive structures of the flower for fertilization. o The micropyle serves as the site for pollen tube entry for fertilization.

Pollen Viability and Preservation o The period of pollen grain víability varies based on temperature

o o

and humidity. Some pollen grains lose viability within minutes of release, while others remain víable for months. Pollen grains can be stored for extended periods in liquid nitrogen (-196°C) for use in brecding programs.

The Pistil

o The gynoccium represents the

female reproductive part of the flower. o It can consist of a single pistil (monocarpellary) or multiple pistils (multicarpellary), either fused

o

-Chalazal pole

Nucellus Embryo sac -Outer integument Inner integument Nucellus -Micropylar pole Micropyle Funiculus

Fig 6: A diagrammatic view of a typical anatropous ovule

SEXUAL

REPRODUCTION

IN FLOWERING PLANTS

Chalazal end

Pollen Germination: Pollen grains form a pollen tube, which grows through the stigma and style. Pollen Tube Entry: The tube enters the ovary through the micropyle and reaches the ovule. o Artifcial Hybridization: Brecding technique used to create desired hybrids by manually controlling pollination. • Emasculation: Removal of anthers from bisexual flowers to prevent self-pollination. Bagging: Covering emasculated or female flowers with bags to protect them from unwanted pollen. Pollination: Controlled pollination is performed using desired pollen, and the flowers are rebagged to prevent contamination. Observing pollen germination can be done by placing pollen grains on a glass slide with sugar solution and observing the pollen tubes under a microscope.

•

Antipodals

Polar nuclei Central cell Egg cell Egg apparatus

Synergids Filiform apparatus

Micropylar end Fic 7: A diagrammatic view

of the mature enmbryo

Pollination

o Defnition: Pollination

is the process of transferring pollen grains from the anther of a flower to the stigma of the same or a diferent flower, facilitating fertilization. o Types of Pollination: 1. Autogamy: Pollination occurs within the same flower, where pollen from the anther fertilizes the stigma of the same flower. 2. Geitonogamy: Pollination involves transferring pollen from the anther to the stigma of another flower on the same plant. 3. Xenogamy: Pollination involves transferring pollen from the anther to the stigma of a flower on a different plant, promoting genetic diversity. o Agents of Pollination: Plants use various agents to achieve pollination, including: • Biotic Agents: Animals such as bees, butterflies, flies, beetles, wasps, ants, moths, birds (sunbirds and hummingbirds), and bats. • Abiotic Agents: Wind and water (less common). o Examples of Pollination by Biotic Agents: • Bees: Dominant pollinators among insects; attracted to colorful, fragrant flowers rich in nectar. • Flies and Beetles: Attracted to flowers with foul odors. • Birds and Bats: Visit specific types of flowers, often brightly colored and rich in nectar. o Outbreeding Devices: Mechanisms to prevent self pollination and encourage cros-pollination. • Synchrony: Timing mismatch between pollen

o

15

release and stigma receptivity. Spatial Separation: Anther and stigma placed at different positions within the flower. mechanism Genetic Self-Incompatibility: ovules. fertilizing from preventing self-pollen • Unisexual Flowers: Some plants have separate male and female flowers, preventing self-pollination. Pollen-Pistil Interaction: The process by which the pistil accepts or rejects pollen based on compatibility. • Pollen Recognition: Pistil recognizes compatible pollen, allowing it to germinate on the stigmna.

Double Fertilization o Double Fertilization: A

o

o

o

unigque

reproductive process in flowering plants where two fertilization events occur within the embryo sac. Syngamy: The first fertilization event where one male gamete fuses with the egg cell to form a diploid zygote. Triple

Scan to know

more about this topic

Double

Fertilization in Angiosperms

Fusion: The second fertilization event where the other male gamete fuses with two polar nuclei to form a triploid primary endosperm nucleus (PEN). Double Fertilization Significance: It ensures the formation of both the embryo and endosperm in the same embryo sac, a crucial adaptation in flowering plants.

Post-Fertilization: Structures and Events Endosperm o Endosperm Development: Occurs before embryo

o

2o

development and provides nourishment to the growing embryo. Types of Endosperm Development: • Free-Nuclear Endosperm: Formation of free nuclei followed by cellularization; found in coconut. • Cellular Endosperm: Endosperm cells form walls; varies in the number of nuclei. Endosperm Fate: Can be completely consumed by the embryo (e.g, peas) or persist in the mature seed (e.g., castor, coconut).

Embryo o Embryo Development: Occurs at the micropylar end of the embryo sac, after endosperm formation. o Embryonic Stages: Common stages in both monocots and dicots: proembryo, globular, heart-shaped, and mature embryo.

o Dicotyledonous Embryo: Contains an embryonal axis with two cotyledons, epicotyl, hypocotyl, and radicle.

Oswaal CUET (UGj Chapterwise Question Bank

16

o Polyembryony: Occurs in some apomictic species where multiple Scan to more kh embryos form in a single seed. abu this tonle o Apomlctic Secd Development: Involves diploid egg cellformation without reduction division or the development of nucellar cells into Apominis an4 cmbryos. Polyembryony o Examples of Apomictic Plants: Some Citrus and Mango varieties exhibit apomikis Polyembryony Observation: Sceds of orange show polyembryony with numerous embryos can t varying sizes in each seed. o Genetic Nature of Apomictic Embryos: Apomiri cmbryos are typically genctic clones of the parent plant o Significance for Agriculture: Apomixis b implications in agriculture, especially for hybrid set production and maintenance, reducing costs for farmer o Research on Apomixis: Active research aims to understand the genetics of apomixis and transfer apomictic genes into hybrid varieties to make hybrid seed production more cconomical.

one cotyledon Monoeotyledonous Epbrvo: Contains an cpicotyl, with (seutellum), an embryonal axis coleorrhiza. encloscd in coleoptilc, and radical

Seed O Seed O

O

O O

o

seed coat(s), Composttlon: Typically consists of

cotyledon(s), and an cmbryo axis. non-albuminous (c.g., pea) Mature Secds: May be a persistent wheat): some have of albunninous (e., mucellus (perisperm). integuments; has from ovule during Secd Coat: Derived gas and water cxchange n micropyle for gemination. water seeds tmaturc, they lose Seed Dehydration: As allowing for storage. dry, and become relatively ofdormancy, secds enter a state Some Seed Dormancy: conditions. under lavorable while others germinate among speccies; sone seeds Seed Vinbility: Varies yecars, with records of exceptionally remain viable for (e.g., date palm, lupine). old secds geminating

o

Apomixis and Polyembryony

reproduction mechanisn in flowering

O Apomixis: Asexual without fertilization. plants, where secds develop

OBJECTIVE TYPE QUESTIONS AJ 1.

MULTIPLE

CHOICE QUESTIONS:

the ovary are called Fruit which develop only from

(CUET 2022]

(a) False fruits (b) Parthenocarpie truits (c) Thue truits (d) Apomictic fruits 2.

Which layer of microsporangium function?

(n) Epidermis (C)

3.

o

tes

(b)

is

nutritive in [CUET 2022]

Endotheciunhni

(d) Tapetum Middle Layers degenerate after fertilisation that sac, cells an the In embryo

are: (a) Synergids and primary endosperm cell (b) Synegids and antipodals (c) Antipodals and primary endosperm cell (d) Egg and antipodals 4. Which one of the cell in an embryo-sac produce endospem after double fertilisation? (b) Antipodal cel! (a) Symergids cell (c) Central Cell (d) Egg S The structure of bilobed anther consists of: (a) 2 thecae, 2 sporangiabgei h 4 (b) 4 thecae, sporangia2 (c) 4 thecae, 2 sporangia (d) 2 thecae, 4 6. From among the situations given below, chose the one that prevents both autogamy and geitonogamy. (a) Monoccious plant bearing unisexual flowers. (b) Dioccious plant bearing only male or female flowers.

sporaneiatt

stdat

bisexual flowers. (c) Monoccious plant with flowers (d) Dioccious plant with bisexual in an embryo 7. Which among the following cell is binucleate

sac? (b) Central cell (a) Antipodal cell (d) Female gamete (c) Synergid are called: 8. Flowers with both androeciumn and gynoecium (b) Anther (a) Bisexual flowers (d) Androgynous (c) Unisexual flowers those that of are not 9. Among the terms listed below, a whorl are: names floral for technically correct

() Androecium (iii) Corolla

(i) (iv)

Carpel Sepal

(b) (iii) and (iv) (d) (i) and (i)8 (c) (ii) and (iv) anatropus a Enclosed within the integument of typical as: known tissue ovule is a diploid mass ofcellular sac Embryo (b) Nucellus Synergids (d Megaspore mother cell. occurs in: During microsporogenesis, meiosis

(a) (i) and (iv)

10.

(a) (c)

I1. (a) Endothecium

(b) Microspore mother cells (c) Microspore tetrads

(d) Pollen grains innermost wall layers of micro 12. The outermost and sporangium in an anther are respectively. (a) endothecium and tapetumn. (b) epidermis and endodermis. (c) epidermis and middle layer. (d) epidernis and tapetum.

FOAL REPRODUCTION IN ALOWERING PLANTS

..The phenomenon observed in some plants wherein parts

of the sexual apparatus are used for forming embryos without fertilisation is called: parthenOcarpy. (a) (b) apomixis, (c) vegetative propagation. (d) sexual reproduction The phenomenon wherein, the ovary develops into a fruit without fertilisation is called (1) parthenocarpy. (b) apomixis. (c) asexual reproduction. (d) sexual reproduction.

.e Inafowcr, if he megaspore mother cell forms megaspores sithout undengoing meiosis and one if of the megaspores develons into an cmbryo sac, its nuclei would be: (a) haploid

)

diploid.

(c) a few haploids and a few diploids. (d) with varying ploidy

16 A diootyledonous plant bears flowers but never produces frits and seeds. The most probable cause for the above situation is: I) Plant is dioecious and bears only pistillate flowers. ) Plnt is dioccious and bears both pistillate and staminate

fiowers. (c) Plant is

monoecious.

(o Plant is dioccious and bears only staminate flowers. 17, While planning for an artificial hybridisation programme involving dioccious plants, which of the following steps would not be relevant?

(a) Bagging of female flower (b) Dusting of pollen on stigma (c) Emasculation

() Collection of pollen 18. From the statements given below, choose the options that

are true for a typical female gametophyte of a flowering plznt. ) Itis &-nucleate and 7-celled at maturity. (H) tis free-nuclear during the development. (ü) hissituated inside the integument but outside the nucellus. r) It has an egg apparatus situated at the chalazal end. (b) (ii) and (iii) (2) ()) and (iv) (e) i) and (ii) (d) (ii) and (iv) 19. Which of these are the carriers of male gametes in some sced plants? (a) Microspore mother cells (b) Pollen Grains (c) Anthers (d) Megaspore mother cells Ans. 20. Select the appropriate options with reference to post fertilisation changes in angiosperms. A. Inner integument of ovule develops into tegmen. B. Ovary wall forms pericarp. C. Ovule forms fruit. D. Zygote forms endosperm. E. Outer integument of ovule develops into Testa. Choose the correct answer from the options given below: (a) B, E only (b) A, B, E only (e) C,D, B only A, C, B only Ans. (d

17 21. Which of the following is a post-fertilisation event in [NCERT Exemplar, Q. 17, Pe. 4] flowering

plants? (a) Transfer of pollen grains (b) Embryo development (c) Formation of flower (d) Formation of pollen grains 22. Choose the correct statement from the following. [NCERT Exemplar, Q. 17, Pg- 14] E0 (a) Cleistogamous flowers always exhibit autogamy. (b) Chasmogamous lowers always exhibit geitonogamy. (c) Cleistogamous flowers exhibit both autogamy and geitono gamy.

(d) Chasmogamous flowers never exhibit autogamy. 23. A Particular species of plant produces light, nonsticky pollen in large numbers and its stigmas are long and feathery. These modifications facilitate pollination by |NCERT Exemplar, Q. 12, Pg. 11| (a) insects. (b) water. (d) animals. (c) wind. 24. The male gametes of rice plant have 12 chromosomes in their nucleus. The chromosome number in the female gamete, zygote and the cells of the seedling will be INCERT Exemplar, Q. 6, Pg. 2] respectively. (b) 24, 12, 12. (a) 12, 24, 12. (d) 24, 12, 24. (c) 12,24, 24. 25. The statements given below describe certain features that are observed in the pistil of flowers. [NCERT Exemplar, Q. 8, Pg. 2] (i) Pistil may have many carpeis. (ii) Each carpel may have more than one ovule. (iii) Each carpel has only one ovule. (iv) Pistils have only one carpel. Choose the statements that are true from the options below. (a) (i) and (ii) (b) (i) and (iü) (c) (ii) and (iv) (d) (iii) and (iv) 26. In a fertilised embryo sac, the haploid, diploid and triploid [NCERT Exemplar, Q. 14, Pg. 11] gn structures are (a) synergids, zygote and primary endosperm nucleus. (b) synergids, antipodal and polar nuclei. (c) antipodal, synergids and primary endosperm nucleus. (d) synergids, polar nuclei and zygote. 27. The number of chromosomes in the shoot tip cells of a maize plant is 20. The number of chromosomes in the microspore mother cells of the same plant shall be (NCERT Exemplar, Q. 18, Pg. 4] (a) 20. (b) 10. 40. (c) (d) 15. a can occur in chasmogamous flower if 28. Autogamy INCERT Exemplar, Q. 10, Pg. 10] 0 (a) pollen matures before maturity of ovule. (b) ovules mature before maturity of pollen. (c) both pollen and ovules mature simultaneously. (d) both anther and stigma are of equal lengths. 29. Embryo sac is to ovule as is to an anther, (a) stamen (b) filament (c) pollen grain (d) androecium INCERT Exemplar, Q.2, Pg. 9]

Oswaal CUET(UG) Chapterwise Question Bank BIOLOG

18

BASED

30. In a typical complete, bisexual and hypogynous the arrangement of floral whorls on the thalamus from ne outermost to the innermost is. Exemplar, Q. 3, Pg. 9l

|NCERT (a) calyx, corolla, androccium and gynoccium.

B

(b) calyx, corolla, gynoccium and androccium. (©) gynoccium, androccium, corolla and calyx. (d) androecium, gynoccium, corolla and calyx. [B]

ASSERTION & REASON:

Directions for Ouestions Number 1-10 statements, namely, consists of two the correct Cach question selecting (R).For Assertion (A) and Reason answer, use the following code: are the true and Reason and Reason (R) (a) Both Assertion (A) explanation ofAssertion (A). (b)

(c) (d) 1.

2.

3.

(R) is a correct are the true but Reason and Reason (R) Both Assertion (A) explanation ofAssertion (A). (R) is not a correct Reason (R) is false. Assertion (A) is true and Reason (R) is true. Assertion (A) is false and microsporangium is generally Assertion (A): The layers. surrounded by three wall tapetum, wall layer, the innermost Reason (R): The grains. nourishes developing pollen primarily of a pollen grain is Assertion (A): The exine pectin. composed of cellulose and resistant to environmental Reason (R): The exine is highly content. factors due to its sporopollenin inner wall is called the grain's Assertion (A): The pollen

up exine. the intine, is made Reason (R): The inner wall, called of sporopollenin. are released with the Assertion (A): Pollen grains dehiscence of the anther. closed to protect the Reason (R): The anther remains pollen grains. a pollen grain is 5: Assertion (A): The generative cell within cell. vegetative the larger than are shed Reason (R): In some angiosperms, pollen grains in a 3-celled stage. remain 6. Assertion (A): In many angiosperms, pollen grains

7.

8.

9.

10.

viable for months. of Reason (R): The viability pollen grains is influenced by temperature and humidity. Assertion (A): The micropyle serves as the site for pollen tube entry into the ovule. Reason (R): The egg apparatus is located at the chalazal end of the embryo sac. Assertion (A): The style is responsible for providing a landing platform for pollen grains. Reason (R): The stigma is the elongated slender part of the pistil. Assertion (A):The endosperm in seeds can be completely consumed by the embryo. Reason (R): Some seeds have a persistent nucellus known as perisperm. Assertion (A): Apomixis is a reproductive mechanism where seeds develop without fertilization. Reason (R): Polyembryony can occur in apomictic species, resulting in multiple embryos in a single seed.

QUESTIONS: rCI COMPETENCY/CASE following paragraph and answer the I. Read the n questions. a

Flowering plants,

or

angiosperms, exhibit proccss. Before the

complex

visibleemmergen fascinating reproductive hormonal a flower, of the plant undergoes flor strucbr of floral primordium.n. changes, initiating the development Thi of inflorescences that bear process involves the formation development ofthe male buds, leading to the differentiation and (androecium) and female (gynoccium) reproductive stne Th of stamens, while within the flower. The androecium consists female reproductive organ. Withinte represcnts the gynoecium te wt stamen, a microsporangium houses the pollen grains,rema exhibit grains the male gametophytes. These pollen ornamentation. diversity in size, shape, and What are the two primary reproductive structures 1. within a flower? (a) Stamens and petals ovule (b) Anther and and gynoecium Androecium (c) (d) Filament and style What is the role of the microsporangium within a 2, stamen? (a) It houses the female gametophyte. deposition. (b) It is the site of pollen pollinators. nectar for (c) It stores (d) It protects the ovule. outermost layer of the pollen grain responsible 3. What is the factors? for its high resistance to environmental Cytoplasm (b) (a) Intine (d) Tapetum (c) Exine are pollen grains typically development stage of At what 4. shed from the anther? (b) 2-celled stage (a) 1-celled stage (d) 4-celled stage stage (c) 3-celled serves as the site for 5. What is the term for the structure that fertilization? during ovule pollen tube entry into the Micropyle (b) (a) Chalaza (d) Integuments (c) Synergids answer given questions 5-10. and paragrapgh the I. Read process in the a Pollen development in angiosperms is crucial a series of intricate involves It plants. reproduction of flowering which cary steps that result in the formation of pollen grains, the .Understanding necessary fertilization. for the male gametes pollen of features stages of pollen development and the unique reproductive biolögy grains is essential for comprehending the fo

of angiosperms.

Table: Pollen Development in Angiosperms

Stage 1.

Microsporo genesis

Description

Four wal! layers in the

Formation of microspore tetrads within

2Key

Characteristics

themicrosporangium

microsporangium 2.

3

Microspore Formation

Microspores develop from pollen mother cells

Pollen Grain Structure

Mature pollen grain composition

Microspore tetrads, each containing potential pollen cells

Exine (sporopollenin) and intine (cellulose layers and pectin)

SEXUAL

REPRODUCTION IN FLOWERING PLANTS

19

Viability and

Factots affecting Temperature and pollen grain humidity influence viability viability Process of pollen $. Pollen Pollen tube enters Germination tube formation the ovule through and growth the micropyle ie table summarizes the key stages of pollen development e angiosperms, nciuding microsporogenesis, microspore ration, the structure of a pollen grain, factors influencing hility, and the process of pollen germination. Each stage has niue characteristics and contnbutes to the successful repro duction of flowering plants. During which stage of pollen development do microspore Storage

tetrads form? (2) Microsporogenesis (b) Pollen Viability (c) Pre-fertilization (d) The Generative Stage 1. What is the primary function of the tapetum in the microsporangium?

(a) (b) (c) (d) 8.

(a)

(c) 9.

(a) (c) 10.

(a) (b) (c)

(d)

Nourishing the developing pollen grains Protection against environmental factors Formation of the exine layer Maturation of the vegetative cell Which part of the pollen grain contains the male gametes? (b) Intine Exine (d) Generative cell Vegetative cell In which part of the flower does thc pollen tube enter during fertilization? (b) Style Stigma Ovary (d) Micropyle What is the primary factor that influences the duration of pollen grain viability? The number of microsporangia The thickness of the exine Temperature and humidity The size of the vegetative cell

ANSWER KEY {AJ

1.(c)

2.

(d)

4. (c) 14. (a) 24. (c)

11. (b)

12. (d)

13. (b)

21.(6)

22 (a)

23. (C)

1.(2)2. 1.(c)

(d) 2. (b)

MULTIPLE CHOICE QUESTIONS

3. (b)

|3. (b) 3.

(C)

5.(d) 15. (b) |25.(a)

6. (b)

7. (b)

16. (d)

17. (c)

8. (a) 18. (c)

| 26. (a)

27. (a)

28. (c)

9.(c) 19. (b) 29. (c)

10. (a) 20. (b)

30. (a)

[B] ASSERTION & REASON |4. (c)

|5.() 8. (c) 6. (a) |7.(a) IC] COMPETENCYICASE QUESTIONS BASED 4. (b)

5.(b)

6.

(a)

|7.(a)8.(d)

9.(a)

10. (a)

9.(d)

10. (c)

ANSWERS WITHEXPLANATION [A MULTIPLE CHOICE QUESTION: Option (c) is correct Eplanation: Fruit which develops only from the ovary are called true fruits, while in false fruits, parts other than ovary also contributes in its formation 2. Option (d) is correct 1.

Esplanation: Tapetum provides nourishment to developing pollen grains and it is the innermost wall layer of microsporangium. While layers like epidermis, endothecium and middle layers perfom the function of protection and help in dehiscence of anther to relcase pollen 3. Option (b) is correct. Explanation: In an unfertilised embryo sac, the antipodals and synergids are distinctly present at chalazal cnd and micropylar end respectively while, in fertilised embryo sac, antipodals and synergids gradually degenerale after the formation of zygote. 4. Option (c) is correct Eplanation: In female gametophyte.central cell is involved in the double fertilisation that help in the endosperm development. While antipodal cells provides nourishment to the cgg cell, and synergid cell help in pollen tube growth.

5. Option (d) is correct. Explanation: Anther is a sac-like structure that produces pollen grains. It is bilobed and each lobe has two theca i.e., dithecous 6. Option (b) is correct. Explanation: Dioecious plants (bearing only mae or female flowers) prevent both autogamy and geitonogamy. Autogamy is a method of self-pollination in which the transfer of pollen

grains from anther to stigma of the same flower. takes place. Geitonogamy the transfer of pollen grains from anther to stigma of another flower of the same plant. It is ecologically cross - pollination which is supposed to be equivalent to self pollination because all flowers on a plant are genetically identical. 7. Option (b) is correct. Explanation: Central cell form binucleate endosperm

mother cell upon fertilisation with one of the two sperm cells, forms triploid cndosperm to nourish embryo development. 8. Option (a) is correct. Explanation: Androecium is the male part and gynocciun is the female part, and in those flower have both of these they are called bisexual flower.

Oswaal CUET(UG) Chapterwise Question Ba

20 Option (c) is correct. Evplanation: All the four whorls

9.

the plant with their can be indicated througlh following rclative position in flower a whorl, called as calyx diagram. Sepals collectively form known as gynoccium. The floral while technically the carpel is stamens arc called as corolla and whorls formed by petals and androccium, respectively. of

Option (a) is correct. anatropous ovule, several structures Evplanation: In a typical nucellus. Let's break down can be found, and one of them is the 10.

the components: 1,

to the orientation of the Anatropous ovule: This refers an ovary. Anatropous ovules are bent at ovule within the the micropyle (the opening through which

angle, with the fertilization) and funiculus (the pollen tube enters during to the ovary) at stalk-like structure that attaches the ovule

opposite ends. This is the structure 2. Diploid mass of cellular tissue: layers enclosed within the integument (he protective diploid. is indeed surrounding the ovule) and mass of cellular tissue enclosed 3. Nuccllus: The diploid anatropous ovule is within the integument of a typical a crucial role in plays called the nucellus. The nuccllus sac, is part of the which cmbryo the the development of female reproductive structure of the flower. answer is (A) Nuccllus because So, in summary, the correct it is the diploid mass of cellular tissue enclosed within the integument of the anatropous ovule.

Option (b) is correct. Eyplanation: During microsporogenesis, meiosis occurs in microspore mother cells. As the anther develops, the microspore mother cells of the sporogenous tissue undergo meiotic divisions to form microspore tetrads. The microspore tetrad after dehydration is developed into pollen grains. 12. Option (d) is correct. Explanation: The outermost and innermost wall layers of microsporangium in an anther are respectively, cpidermis and tapetum. A typical microsporangium is generally surrounded by four-wall layers, that is, the epidermis, (outermost protective layer), endothecia, (middle fibrous layers) and the tapetum (innermost nutritive layer). 13. Option (b) is correct. Explanation: Apomixis refers to the formation of seeds without fertilization. The embryos are genetically identical to the parental plant. 14. Option (a) is correct Explanation: Parthenocarpy is the formation of seedless fruits without fertilization. The fruits developed from unfertilised ovary are called parthenocarpic fruits. 15. Option (b) is correct. egg cell is formed Explanation: In some species, the diploid into an embryo and develops division reduction without occurs without fertilisation. It is an asexual reproduction which or extreme environments. in in the absence of pollinators correct. is (d) 16. Option Explanation: In dioecious plants, the unisexual male flower is staminate, that is, bearing stamens only, while the female is fruits and pistillate or bearing pistil only. For the production of 11.

seeds fertilisation must take place, which possible presence of both male and female flowers, When the pla dioccious, will give rise the following

is

it

to

situations:

is dioccious and bears only pistillate flowers, fertiliva, can take place with the help of pollinators. (ü) the If dioccious and bears only staminate flowers, fertilisationplat, catty take place, because female gamete is non-motile which reach the male gamete in order to fuse with it. When tthe is monoecious, that is, carrying both stamen and pistil plan togete, it may lead to self-fertilisation and production of seed plunt

Option (c) is correct. Explanation: Artificial hybridisation is one of the maye. methods of crop improvement programme. This crose make sure that only the desired pollen grains are used pollination and the stigma is protected from contamins (from unwanted pollen). This is achieved by emasculation nd bagging techniques. 18. Option (c) is correct. 17.

Explanation: Statement () and (11) are correct regardinn female gametophyte of flowering plant. The female

Jocated inside the nucellus gametophyte or embryo sac enclosed within the integuments. In a majority of flowering plants, one of the megaspore is functional while the other three degenerates. Three repeated mitotic divisions of the functional megaspore results in the formation of seven-celled or cight-nucleate embryo sac. Six of the eight nuclei are organised at the two poles. Three cells grouped at micropylar end forms cgg-apparatus and 3 at the chalazal end fom antipodal cells. The large central cell at the centre has two polar nuclei. The meiotic divisions in the formation of embryo sac are strictly free nuclear, that is nuclear divisions are not followed immediately by cell-wall formation. Gametophyte is situated at micropylar end not at chalazal end. 19. Option (b) is correct Explanation: Pollen grain carries the male gametes which can be transferred to the female gamete via pollination. All pollen the events from pollen deposition on the stigma until tubes enter the ovule interaction.

are together referred as pollen-pistil

20. Option (b) is correct a. Explanation: Post fertilization events includes Development of endosperm from primary endosperm cell. b. Development d. At of embryo from zygote c. Formation of seed from ovule Secu an into develops integument the time of seed formation, while coat) seed testa (outer forms coats. Outer integument e. nner integument forms tegmen (inner seed coat). Formation of pericarp from ovary wall 21.Option (b) is correct even Explanation: During the sexual reproduction, the are calleo zygote which take place after the formation of developmen process embryo of post-fertilisation events. The from the zygote (called embryogenesis) takes place a inside fertilisation. In all floweringB plants, the zygote is formed forn the ovule. In ovule, the zygote divides several times to an embryo. 22. Option (a) is correct flowers is Explanation: The pollination that occurs in opened self-pollination called chasmogamy, It is of two types, that is, two is of (autogamny) and cross-pollination. Cross-pollination

e

SEXUAL

REPRODUCTION IN FLOWWERING PLANTS

ypes, that is, geitonogamy and xenogamy. So, we can say that chasmogamousi sflowers exhibit both: autogamy (self-pollination) allogamy (crosSspollination). While, in cleistogamous theanthers and stigma lies close to each other within the closed flowers. When anthers dehisce inthe flower buds, pollen contact with the stigma grains come in for effective pollination. ne these fiowers are nvanably autogamous as there is no chance of cross-pollen landing on the stigma 23.Option (c) is correct Erolanation: Plants use two abiotic (wind one hioic (animals) agent to achieve pollination.and water) and Majority plants of nGe biotic agents for pollination. Pollination by wind is more common amongst abiotc pollnation. It requires the light and nn-sticky pollen grains so that, they can be transported in wind urents. They often possess well-exposed stamens (so the that pollens are easily dispersed into wind curents) and large often feathery stigma to easily trap air-borne pollen grains. Wind nollination is common in grasses. Pollination by water is called byrophily which is quite rare in flowering plants but occurs in aquatic plants. Zoophily is pollination through the agency. Entomophily (pollination by insects) is the most common type of zoophily which occurs through the agency of animals. 24. Option (c) is correct Eplanation: In female gamete, the chromosome number will be same as that of the male gamete (12). A zygote is a fertilised egg'seed which means gametes from the parents have been combined (diploid) and thus, the chromosome number will be 24 (2n). A seedling is a young plant. Sporophyte develops out from a plant embryo from a seed. So, the chromosome number in the cells of the seedlings will be 24 (2n), which will further give rise to new diploid individual. Female gamete (n) = 12 Zygote (2n) = 24 Cells of seedling (2n) = 24 Q. 25. Option (a) is correct Explanation: (a) Pistil is the female reproductive part (gynoecium) of a flower. It is centrally located and consists of ovary (a swollen base), which contains the potential seeds or ovules; style (a stalk), arising from the ovary; and a pollen receptive tip, the stigma. Inside ovary it is attached to a parenchymatous cushion called placenta, either singly or in cluster.

26. Option (a) is correct Explanation: In a fertilised embryo sac, the haploid, diploid and triploid structures are synergids, zygote and primary endosperm nucleus respectively. 27. Option (a) is correct Eplanation: The whole plant body of maize plant including shoot tip cells remains in dploid (2n) condition. As the organ, the microspore mother cell is a part of reproductive same as the remain will cells these in number Chromosome individual, that is, 2n = 20. These microspore mother cells are Turther responsible for producing male gametes, that is, haploid (n) by reduction division 28.Option (c) is correct a tplanation: Autogamy is a method of self-pollination. It is a Process in which the stigma of flower receives pollens from Lue anther of same flower. For autogamy both the sex organs same time. a chasmogamous flower should mature at the open at maturity, pollen release chasmogamous flowers sagma receptivity should be synchronised for the process the length of anther and stigma lganmy. In such inflowers, Secondary role autogamy, e.g., in case of protandry (in PyS which pollens mature early) and protogyny (in which stigma ntures carly) leads to cross-pollination. S

21 29. Option (c) is correct Explanation: The pollen grains reprevet the male gametophytes. As the anthers mature znd detrydrse, the microspores dissociate from each other znd develop ito polle grains. So, embryo s2c is to ovule 25 pollen grzin is to 2n ather.

30. Option (a) is correct Explanation: In a typical complete, bisexual znd bypogEYDOS ffower the arrangement of fioral whoris on the thalznus from the outermost to the innermost is as folloas: (i) Cayx: It is the outermost whorl of sepals. (ii) Corolla: It is a whori of petais inside the calyx. (iii) Androecium: It is a whori of stamens inside the corolla. (iv) Gynoecium: It is a whorl of pistils (in the centre of the flower forming inner most whoris).

[B. ASSERTIONAND REASON QUESTIONS: correct

1. Option (a) is

Explanation: Assertion (A) corectly mentions that the microsporangium is generally surrounded by three wall layers. Reason (R) provides the correct explanation by specifying that the innermost wall layer, the tapetum, nourishes developing pollen grains. 2. Option (d) is correct Explanation: Assertion (A) is incorect because the exine is primarily composed of sporopollenin, not cellulose and pectin. Reason (R) corectly explains the resistance of the exine to environmental factors. 3. Option (b) is correct Erplanation: Assertion (A) is correct in identifying the inner wall as the intine, not the exine. Reason (R) is not the correct explanation because the intine is not made up of sporopollenin. 4. Option (c) is correct Explanation: Assertion (A) is corect as pollen grains are indeed released with the dehiscence (opening) of the anther. Reason (R) is not corect because the anther opens to facilitate pollen release, not to protect the pollen grains. 5. Option (d) is correct Explanation: Assertion (A) is incorect because the generative cell is typically smaller than the vegetative cell in a mature pollen grain. Reason (R) is correct as some angiosperms shed pollen grains when they are ina3-celled stage. 6. Option (a) is correct Eplanation: Assertion (A) is correct, as many angiosperms indeed maintain pollen viability for months. Reason (R) provides the correct explanation by stating that the viability of pollen grains is infiuenced by factors like temperature and humidity.

s

7. Option (a) correct Explanation: Assertion (A) is corect because the micropyle is indeed the site for pollen tube entry into the ovule. Reason (R) provides the correct explanation by specifying the location of the egg apparatus. 8. Option (c) is correct Explanation: Assertion (A) is correct in describing the function of the style. Reason (R) is not correct because the stigma is typically the receptive surface for pollen grains, and it is not the elongated slender part of the pistil. 9. Option (a) is correct Eplanation: Assertion (A) is comect because the endasperm in some seeds can be fully consumed by the developing embryo.

Reason (R) provides the correct explanation by mentioning the presence of a persistent mucellus known as perispen in some seeds.

22

Oswaal CUET(UG) Chapterwise Question

10. Option (a) is correct

Explanation: Assertion (A) is correct in describing reproductive mechanism without fertilization. apomixis Reason (R) provides the correct explanation by mentioning polyembryony, which can occur in apomictic species, leading to the development of multiple embryos within a single secd. as a

[C] COMPETENCY/CASE-BASED QUESTIOONS: 1.Option (c) is correct Explanation: The androecium represents the male reproductive structures of a flower, and it includes the stamens. The gynoecium represents the female reproductive structures and includes the pistil or carpel. Together, the androecium and gynoecium are the two main reproductive parts within a flower.

2. Option (b) is correct Eplanation: The microsporangium is the part of the stamen where pollen grains are produced and stored. It acts as the site where pollen grains are deposited, making it available for pollination when the flower is ready to reproduce. 3. Option (c) is correct Eplanation: The outermost layer of a pollen grain is called the exine. It primarily consists of sporopollenin, a substance known for its high resistance to environmental factors such as heat, chemicals, and physical damage. This robust exine layer protects the pollen grain during its journey to the stigma. 4. Option (b) is correct Explanation: Pollen grains are typically shed from the anther in the 2-celled stage. At this stage, each pollen grain contains

two cells: the vegetative cell and the generative

is well-suited for pollination,, as

participate in fertilization.

,

6. Option (a) is correct

Explanation: Microsporogenesis is the stage wheremicrospor: tetrads form within the microsporangium. 7. Option (a) is correct Explanation: The tapetum nourishes developing pollen gri. within the microsporangium. 8. Option (d) is correct Explanation: The generative cell within the pollen gz contains the male gametes responsible for fertilization. 9. Option (d) is correct Explanation: The micropyle is the site where the pollen tube

enters the ovule for fertilization. 10. Option (c) is correct Explanation: The duration ofpollen grain viability is infuence!

by external factors such as temperature and humidity. Optimat conditions can extend pollen viability. These questions should provide a more challenging assessmert of your knowledge regarding pollen development in angi osperms.

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5. Option (b) is correct Explanation: The micropyle is the smal opening at the ovule's integuments. It serves as site for pollen the entry into the ovule during fertilization. tiby Thepollen tube through the micropyle to reach the ovule, facilitaing fertilization process. te

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3

HUMAN REPRODUCTION

Revision Notes o Humans are sexually reproducing and viviparous, meaning they give birth to live offspring.

o The reproductive events in humans involve a series of intricate pro cesses that lead to the formation of a

new individual.

Scan to know more about this topic

Spermatozoa Spermatid

Secondary spermatocyte

Human

Primary spermatocyte

reproduction

Male Reproductive System o Primary Sex Organs: Testes, a pair of oval-shaped organs, are the primary

male sex organs. They are located outside the abdominal cavity in a sac called the scrotum, which helps maintain a lower temperature essential for spermatogenesis, the process of sperm production. Within each testis, there are approximately 250 testicular lobules, each containing highly coiled seminiferous tubules where sperms are produced. The seminiferous tubules are lined with two types of cells: spermatogonia (male germ cells) and Sertolicells, which play a crucial role in nurturing and supporting developing spermatogenic cells. Surrounding the seminiferous tubules are Leydig cells, also known as interstitial cells, responsible for synthesizing and secreting androgens, including testosterone, which are essential for male sexual characteristics and function. o Secondary Sex Organs: The male duct system includes rete testis, vasa efferentia, epididymis, vas deferens, ejaculatory duct, and associated glands. Urinary bladder

Ureter Vas deferens

Seminal vesicle Prostate Bulbourethral

gland

Epididymis

Urethra

Vasa efferentia

Rete testis Testicular lobules

Testis

Glans

-Foreskin

penis

Fig 1: Human Male Reproductive System

Sertoli cell Spermatogonium Fig 2: Sectional view of human seminiferous tubule

The epididymis is a coiled tube where sperm from the testes mature and gain motility. The vas deferens, which ascends into the abdominal cavity and loops over the urinary bladder, carries sperm from the epididymis. The ejaculatory duct receives secretions from the seminal vesicles and opens into the urethra. The urethra, originating from the urinary bladder, extends through the penis to its external opening called the urethral meatus. Together, these ducts store and transport sperm from the testes to the outside through the urethra.

o External Genitalia: The penis, the primary external male genital organ, plays a crucial role the process of insemination. •It contains specialized tissues that facilitate erection, allowing for the introduction of sperm into the female reproductive tract. The enlarged end of the penis is known as the glans, and it is typically covered by a loose fold of skin called the foreskin.

o Accessory Male Genital Glands:

.

Paired seminal vesicles, the prostate gland, and paired bulbourethral glands (Cowper's glands) make up the accessory male genital glands. These glands secrete various components that together constitute seminal plasma, a fluid rich in fructose, calcium, and certain enzymes. Seminal vesicles are responsible for producing the majority of the semen, typically contributing to about 60-70% of its volume.

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Bank Question

Chapterwise (UG) CUET Oswaal

24

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ygote

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PUMAN REPRODUCTION

cTi

25

The secretion of the bulbouretlhral glands is alkaline and mucous-rich, aiding in lubricating the penis, supplying nutrients to the sperm, and counteracting the acidic environment of' the female reproductive

o Secondary Sex Organs: The female duct system comprises a pairoffallopian tubes (oviducts), a uterus, cervix, and vagina. Each fallopian tube extends from the periphery of an ovary to the uterus. The section closer to the ovary is a funnelshaped structure called the infundibulum,

•

tract.

Female Reproductive System o Primary Sex Organs:

• y

o

which has finger-like projections called fimbriae.

The primary female sex organs are a pair of ovaries, which serve as the site for the production of ova (cggs) and the secretion of various steroid ovarian hormones, including cstrogen and progesteronc. These ovaries are located on cither side of the lower abdomen and are connected to the pelvic wall and uterus by ligaments. Each ovary is enveloped by a thin epithelial layer that encloses the ovarian stroma, consisting of an outer cortex and an inner medulla. Within the ovaries, groups of cells form structures known as Ovarian or Graafian follicles, each housing a centrally located ovum.

The fallopian tube further consists of the ampulla, isthmus, and uterinc part.

The uterus, also known as the womb, has an inverted pear shape and is supported by ligaments attached to the pelvic wall. It connccts to the vagina through a narrow passage called the cervix, which forms the cervical canal, serving as part of the birth canal.

The uterinc wall is composcd of threc layers: the cxternal perimetrium, the middle myometrium (consisting of smooth muscle), and the inner endometrium, which undergoes cyclic changes during the menstrual cycle.

Uterine fundus

Uterine cavity Isthmus

Ampulla

Fallopian tube

Infundibulum

t s

Endometrium Myometrium Perimctrium

Ovary

sots

Fimbriac

Cervix

Cervical canal Vagina

Fig 3: Human Female Reproductive system

o Mammary Glands: • A pair of mammary glands, containing glandular

o External Genitalia: • The external female genitalia, collectively referred

tissue and adipose (fat) tissue, is present in the chest region of females.

to as the vulva, includes the mons pubis, labia

majora, labia minora, hymen, and clitoris. The mons pubis is a cushion of fatty tissuc covered

by skin and pubic hair. Labia majora are a pair of thick, fleshy folds of tissue that surround the vaginal opening. Labia minora are narrower folds of tissue located beneath the labia majora. a The vaginal opening is often partially covered by membrane known as the hymen. The clitoris is a small, sensitive structure situated at the upper junction of the labia minora, above the urethral opening.

• •

• s

•

The glandular tissue is organized into 15-20 mammary lobes, each containing clusters of milk secreting cells called alveoli. Milk produced by the alveoli is stored within the cavities or lumens of these structures. Mammary tubules transport milk from the alveoli, and several mammary ducts converge to form a wider mammary ampulla. The lactiferous ducts connect to the lactiferous sinus, through which milk is drawm out during breastfeeding.

26

Oswaal CUET

Question

Gemetagenesk The mces of gamcte fo mation ocHs in the testes And ovares

o

• Spermatogenesis takes placc in the testes, beg inhíng at puberty.

• Oogenesocus

in the

Sean to know more about thls tople

o Centrioles: •

Gametogenesis 1 Iluman

Reproductlon|

\ocate play a crucial role duringcell division, in organiZAng formation of particularly the the mitotic spindle Flagellar Apparatus: duringfertilization. inthe

o

• The flagcllum

development.

arranged in a

Spermatogonia, locatcd within the seminiferous rubules of the testes, undergo mitotic divisions to incTeASe in number.

o

and undergo meiotic divisions to produce secondary spermatocytes, cach with 23 chromosomes. Snematids are formcd from sccondary spermato cytes, and spemiogenesis transforms them into

Coat:

•

o

spermatoz04.

Tbesc mature spermatozoa arc cventually relcased from the seminiferous tubules in a process called spermiation,.

Sperm: Structure of sperm: o Head: • The hcad is the front part of the sperm

o

in

o

Upon puberty, one primary o0cyte typically completes meiosis-1, resulting in the release a of secondary oocyte during cach menstrual cycle. • This secondary o0cyte is arrested and only completes meiosis-II uponin metaphase-1| fertilization by a sperm. Ovum: The ovum is a specialized female reproductive cell with a unique structure designed to support fertilization and early embryonic development. It contains a nucleus with genetic material, a nutrient-rich cytoplasm, protective layers (zona pellucida and corona radiata), and various organelles essential for cellular processes.

o Tail (Flagellum): The tail is a long, whip-like structure extending from the idpiece.

.

for thesperm's motility, allowing it to swim in scarch of the cgg for fertilization. The flagellum has a complex arrangement of microtubules that forn the axoneme, which provides the structural support for movement.

o Plasma Membrane:

•

The plasma membrane surrounds the entire sperm

cel. It contains receptors that can recognize and bind to specific molecules on the surface of the egg during fertilization.

0 Acrosomal Vesicle:

•

This is a membrane-bound structure within the acrosome,

• IIcontains enzymes necessary for breaking down

the outer layers of the cgg, allowing the sperm to penetrate and fertilize it.

the

Oogenesis: Oogenesis begins during embryonic when millions development ofoogonia (gamete mother cells) are formed in the fetal ovaries. Primary 00cytes, derived from oogonia, are arrested in prophase-I of meiotic division.

The acrosome is a cap-like structure covering the front part of the nucleus. Iu contains enzymes that help the sperm penetrate the egg during fertilization.

• Itis responsible

movement.

The sperm's plasma membrane glycoproteins, which are involvedis coated with recognition and sperm-egg binding.

Sperm Tail Sheath: The tail is enclosed by a sheath that the sperm for helps streamlins

cell.

Midpicce:

•

microtubules

cfficient movement through female reproductive tract.

It contains the nucleus, which carries the genctic material (DNA) of the sperm.

The midpicce is the region just behind the head. It contains numerous mitochondria, which provide nergy (in the form ofATP) for the sperm's movement. Mitochondria are arranged a spiral or helical pettem within the midpicce.

ofthe sperm "9+2" pattern. contains

• This arrangement providesthees and allows structural for coordinated, framewok whip-1ke Glycoprotein

Smatogonia then differentiate into spermatocytes

o

Spcrmn

typically have a near the pair of nucleus, ccntrioles Centrioles

o Spermategenesis:

•

BankABIOLOGY

microtubules

ovaries, starting during embryonic

•

(UG) Chaptervise

Structure of Ovum o Nucleus:

•

The nucleus of the ovum contains a haploid of chromosomes (half the normal number chromosomes in most human cells).

set of

carries the genctic material necessary for fertilization and the development ofa new organism. It

o Cytoplasm: • The cytoplasm of the ovum

is rich in nutrients and

organelles. It provides the necessary energy and resources betoi the initial stages of embryonic development

implantation in the uterus.

o Plasma Membrane (Cell Membrane): ovu • The plasma membrane surrounds the entire controls • It acts as a selectively permeable barrierrt hat out of the cell. the entry of substances into and

HUMAN

REPRODUCTION

27

o Zona Pellucida: • The zona pellucida is an extracellular matrix or glycoprotcin layer surrounding the plasma membrane of the ovum.

o Ovulatory Phase: Takes place around the 14th day of the mernstrual cycle. LH and FSH levels peak. A surge in LH induces ovulation, the release ofa mature cgg (secondary oocyte) from the ovarian follicle.

It plays a critical role in sperm-cgg recognition and

binding

uring fertilization.

o Corona Radiata: • The corona radiata consists of layers of granulosa cells that surround the ovum. These cells are connected to the ovum by long, hair

o

like structures called cumulus oophorus. The corona radiata helps protect and nourish the ovum as it moves through the female reproductive tract. Vesicles and Organelles: • The cytoplasm of the ovum contains various vesicles and onganelles, including Golgi apparatus, endoplasmic reticulum, mitochondria, and lysosomes. • These organelles are involved in processes such as protein synthesis, energy production, and cellular metabolism.

o Polar Body (sometimes): C

In some cases, a polar body may be present. A polar body is a smaller cell that is produced during oogenesis and contains a minimal amount of cytoplasn. The polar body is a byproduet of the unequal division of cytoplasm during meiosis and typically does not play a role in fertilization.

o Luteal Phase:

o

Fertilisation and Implantation o Fertilisation is the process of the fusion ofa sperm cell

with an ovum (egg) to form a zygote. o During sexual intercourse (coitus), semen is ejaculated into the vagina. ŠvO Spermatozoa swim rapidly through the female reproductive tract to reach the ampullary-isthmic junction of the fallopian tube, where fertilization typically occurs. o The acrosome of the sperm undergoes an acrosomal reaction, releasing enzymes that dissolve the egg's protective layers, allowing the sperm to penetrate the egg.

OCortical

•

Menstrual Cycle

o

The menstrual cycle is a complex hormonal physiological Scan to know and more about process that occurs in females and this topic is typically around 28 days long. o Itconsists of four phases: mnenstrual, follicular, ovulatory, and luteal. o Homonal regulation involving FSH The Menstrual Hormone) (Follicle-Stimulating Cycle and LH (Luteinizing Hormone) orchestrates the events of the menstrual cycle. o Each phase is characterized by specific changes in the female reproductive tract and hormone levels.

•

LH and FSH production is reduced.

o Follicular Phase:

Typically occurs from cycle days 6-13 or 14. • FSH stimulates. ovarian follicles to produce

cstrogen. Estrogen promotes the proliferation of the endometrial lining, increasing the number of uterine glands and blood vessels.

Reaction:

After sperm entry, the egg undergoes a cortical reaction to prevent polyspermy (fertilization by multiple sperm). Cortical granules bencath the egg's plastna membrane release chemicals into the space between the ooplasm and the plasma membrane. This elevates the vitelline membrane, creating a fertilization membrane that hinders the entry of additional sperm. Ensuring only one sperm fertilizes the egg prevents genetic abnormalities.

o The haploid gametes, the sperm, and the ovum fuse

o Menstrual Phase: • Lasts from approximately cycle days 3-5. Decreased LH leads to corpus luteum degeneration, reducing progesterone production. The endometrial lining of the uterus breaks down, leading to menstruation.

Occurs from cycle days 15 to 28. The corpus luteum, formed from the ruptured ovarian follicle, secretes progesteronc. The endometrial lining thickens, and uterine glands become secretory. Hormonal fiuctuations and the subsequent changes in the endometrial 1lining are essential for preparing the uterus for potential embryo implantation.

n

to create a diploid zygote. As the zygote begins its journey toward the uterus, it undergoes mitotic divisions, forming a multicellular structure known as a blastocyst. o Implantation: The blastocyst eventually attaches itself to the uterine wall in a process called implantation. Implantation is a crucial step in the establishment of pregnancy, as it initiates the interaction between the developing embryo and the matermal body.

Pregnancy and Embryonic Development Embryonic development in humans can be explained in tems of cellular stages, each representing a crucial step in the formation ofa new individual: o Fertilisation Stage: • Fertilisation occurs when a sperm cell penetrates and fuses with an egg cell (ovum).

Oswaal CUETT(UG) Chapterwise Question Bank BIOLOGT

28 • This fusion results 4

in the formation of a diploid zygote, the first cell of the new individual.

o Cleavage Stage: • The zygote undergoes

o Birth (Parturition) Stage: Scan to know

Parturition marks the end

more about this topic

N

a series

of rapid cell divisions known as cleavage.

Cleavage divisions do not increase the overall size but create a multicellular structure called a morula.

of embryonic and

fetal

development.

6

. It involves uterine ccontractions, cervical changes, hormonal signalsthat lead to the birth offthe baby.2nd

o Postnatal Development Stage: Embryology | Fertilization,

Cieaon Bla week

|First of embryonic development | Zygote

o Blastocyst Formation: Further cleavage divisions transform the morula into a blastocyst. The blastocyst comprises two main parts: the outer trophoblast and the inner cell mass.

o Implantation Stage: • The blastocyst attaches

to the uterine lining (endometrium) in a process called implantation, typically occurring 6-10 days after fertilization. This attachment allows the embryo to receive nourishment from the mother's body.

o Gastrulation Stage: Gastrulation is a key process during which the embryo undergoes reorganization, forming three primary germ layers: ectoderm, mesoderm, and endoderm. These germ layers give rise to different tissues and organs in the body.

o Neurulation Stage: Within the ectoderm, a process called neurulation Occrs.

It leads to the formation of the neural tube, which eventually develops into the central nervous system, including the brain and spinal cord.

After birth, the newbom continues to grOW and outside the womb. develop teostsu • This stage includes further maturation of organs and systems, adaptation to the external environment, of development various and the skills and abilities, o During human embryonic development: • At one month, the embryo's heart begins to form. By the end of the second month, limbs and digits are recognizable. By the end of the third month. • major organs and external genitalia are well developed. • Fetal movement becomes noticeable around the fifth month. By the end of the sixth month, the body is covered fine hair, eyelids form, and the eyes open. . in At the end of nine months, the fetus is fully developed and ready for birth. e

•

Parturition and Lactation o Parturition: Parturition refers to the process of delivering a fully developed fetus and typically occurs near the end pregnancy.

oteofSignals

for parturition originate from the fully developed fetus and placenta. These signals induce mild uterine contractions known as the fetal ejection reflex. The release of oxytocin from the maternal pituitary gland intensifies uterine contractions, leading to the expulsion of the baby from the uterus. O Lactation: • Lactation is the production of milk by the mammary glands.

o Organogenesis Stage: o Organogenesis is the

The mammary glands begin producing milk towards the end of pregnancy. Initially, the milk produced is called colostrum, which is rich in antibodies and essential nutrients. Colostrum provides crucial immune protection to the newborn. As lactation continues, the milk transitions to mature breast milk, providing complete nutrition for the infant.

phase during which cells within the germ layers differentiate and migrate to form specific organs and organ systems. O Major organs like the heart, lungs, liver, and kidneys begin to take shape during this stage.

o Fosetal Development Stage: The embryonic period ends around the eighth week after fertilization, and the developing organism is now referred to as a fetus. During the fetal stage, the focus is on growth and maturation of the organs and tissues formed during organogenesis.

Hormonal Control of Reproductive Processes o Various hormones, including gonadotropin-releasing

o Placental Development Stage: Concurrently with embryonic and fetal development, the placenta, a temporary organ, develops. The placenta plays a crucial role in nutrient and Oxygen exchange between the mother and the fetus.

o

hormone (GnRH), luteinizing hormone (LH), follicle stimulating hormone (FSH), estrogen, and progesterone play pivotal roles in regulating the male and female reproductive systems, menstrual cycle, and pregnancy. The balance and timing of these hormones are crucial for the successful functioning of the reproductive processes outlined

above.i

HUMAN

REPRODUCTION

29

OBJECTIVETYPE QUESTIONS IAIMULTTPLE CHoiCE

IA)

B)

(O

o) (a) (C)

2.

(a) (b)

()

QUESTIONS:NRA

Select the correct statements regarding menstrual cycle in (CUET 2023) human female: The first menstruation begins at puberty and is called menopause. The ovulation takes place in the middle of cycle (about 14h day), when the level of progesterone is at maximum level. In absence of fertilisation, the corpus luteum degenerates which causes the disintegration of endometrium leading to menstruation. In human beings, menstrual cycle ceases around 50 years of age. Choose the correct answer from the options given below: (b) (B) and (D) only (A) and (B) only (d) (C) and (D) only (A) and (C) only Select the hormone which is not secreted by human placenta ? (CUET 2023] Estrogen Progestogen Human chorionic gonadoropmas

(d) Luteinising hormone 3. Select the hormones produced in women only during

pregnancy.

[CUET 2022]

A. Estrogen

D. Human placental lactogen E. Relaxin

Choose the correct answer from the options given below: (a)

Band

only

(d) B, D and E only 4.

(a) (c) 5.

A. B.

C. D.

Which of the following gets embedded in the endometrium [CUET 2022] during implantation? Morula (b) Zygote (d) Embryo Blastocyst events Arrange the following in the female reproductive [CUET 2022] cycle in their natural sequence. Ovulation Growth of corpus luteum Sudden increase in level of LH Secretion of FSH E. Growth of ovarian follicle and Oogenesis Choose the correct answer from the options given below:

(a) (b)

E-D -A-B -C

(c)

E-C-A-D-B

O.

-C-E-B

Which of the following is effect of steroid in males? [CUET 2022]

LÍst 2

Present at the upper part of labia minora

B.

Fimbriae

II.

C.

Clitoris

III. Site of fertilisation IV. Helps in collection of

D. Cervical Canal

Along with vagina is birth canal

ovum after ovulation

(a) (c) 8.

(a) (c) 9.

(a) (c)

A. B

C. (a) (c) 12,

(a) (c)

13. A. B.

Choose the correct answer from the options given below: [CUET 2022] A-IV, B-I, C-II, D-III (b) A-II, B-IV, C-I, D-II A-I, B-II, C-IV, D-III (d) A-II, B-III, C-I, D-IV The Graafian follicle ruptures to release the ovum from the ovary by the process called: [CUET 2022] (b) Menstruation Ovulation (d) Copulation Implantation to 8 16 embryo blastomeres is called The with [CUET 2022] 21 Morula bi (b) Blastula Zygote (d) Foetus The part of the human sperm that helps in the fertilisation of the ovum is a cap-like structure called: [CUET 2022] A1 Head (b) Acrosome Middle piece (d) Tail Layers surrounding the ovum from outside to inside are: [CUET 2022] 2n Zona pellucida Vitelline membrane Corona radiata Choose the correct answer from the options given below: [CUET 2022] A, C, B (b) C, B, A C, A, (d) A, B, C In humans females at the time of birth, the stage of cell cycle of oocyte is: Prophase-I (b) Prophase-II Meiosis-II (d) Mitosis Identify the correct statements. [CUET 2022] An Oogenesis is initiated at puberty. Second meiotic division in secondary oocyte occurs the

Bion

ovary.

C. Middle piece of spern provides energy for movement. D. Fertilisation of gametes occurs in the ampulla isthmic

D-E-C-A.B

(d) D-A

1

A. Ampulla

11.

(b) B and E only (c) A, B and C only

Premature baldness Decpening of voice Excessive hair growth on face and body Enlargement of clitoris Match List-I with List-II

LÍst

(a) (c) 10.

B. Human chronic gonadotroph C. Progesterone

D

(a) (b) (c) (d) 7.

A

region of oviduct. E. Myometrium helps in muscular contractions of the uterus. Choose the correct answer from the options given below: (a) A, D, E only (b) A, B, D only (c) B, C, D

onlytot

(d) C, D, E only

Oswaal CUET (UG) Chapterwie uestion Bar

30 14. Hormones responsible for menstrual cycle are produced

from:

(a) (b) (c)

(d) 15.

[CUET 2022] p0

uterus only ovaries only ovaries and anterior pituitary uterus and anterior pituitary Which one of the following is not a male accessory gland?

(a) Seminal vesicle (b) Ampulla (c) Prostate (d) Bulbo-urethral gland 16. Prostate glands are located below (a) gubernaculum (b) seminal vesicles (c) epididymis (d) bulbourethral glands 17% The membranous cover (a) corona radiata, (c) zona pellucida,

of

theovum at ovulation is (b) zona radiata. (d) chorion,

18. In human adult females oxytocin (a) stimulates pituitary to secrete vasopressin (b) causes strong uterine contractions during parturition

(c) is secreted by anterior pituitary (d) stímulates growth of mammary glands 19, Acrosomal reaction of the sperm occurs due to (a) íts contact with zona pellucida of the ova. (b) reactions within the uterine environment of the female. (c) reactions within the epididymal environment of the male. (d) androgens produced in the uterus. 20, Seminal plasma, the fuid part of semen, is contributed by (() Seminal vesicle

(i) Prostate (IIE)

Urethra (Uv) Bulbo-urethral gland (a) iand ii (b) i, ii and iy t (d) i and iv (c) i, ii and iv 21. Spot the odd one out from the following structures with reference to the male reproductive system. [NCERT Exemplar,Q.3, Pg. 1] A1 (a) Rete testis (b) Epididymis (d) Isthmus (c) Vasa efferentia 22, The vas deferens receives duct fron the seminal vesicle and opens into urethra as:

[NCERT Exemplar, (Q. 14, Pg. 31 (a) cpididymis. (b) cjaculatory duct, (c) efferent ductule, (d) ureter. to meatus 23. Urethral refers the:

(NCERT Exemplar, Q. 15, Py. 4) (a) (b) (c) (d)

urinogenital duct, opening of vas deferens into urethra, extermal opening of the urinogenital duct, muscles surrounding the urinogenital

duc.h-tss

24. Identify the odd one from the following.

(NCEKT Exemplar,

).

12, Py 4]

(b) Finbriae (a) Labia minora Isthmus (d) Infundibulun (c) wrong the following statement from 25. Jdentify the

(NCERT Exemplar, Q.2,Pe J|

g

(a) High levels of oestrogen tri2gers the ovulatory surge. (b) Oogonial cells start to proliferate and give rise to furgti ova in regular cycles from puberty onwards. (e) Sperms released from seminiferous tubules are prty

motile/non-motile. ot (d) Progesterone level is high during the post ovulatory of menstrual cycle. 26. The immature male germ cells undergo division to produe sperms by the process of spermatogenesis. Chose te correct one with reference to above.

[NCERT Exemplar, Q.9, Pe2) (a) Spermatogonia have 46 chromosomes and always undergo meiotic cell division. (b) Primary spermatocytes divide by mitotic cell dívision.

(c) Secondary spermatocytes have 23 chromosomes and undergo second meiotic division. (d) Spermatozoa are transformed into spermatids. 27. Spermiation is the process of the release of sperms from (a) (c)

28.

[NCERT Exemplar, Q. 5, Pg. 2] B seminiferous tubules. (b) vas deferens. epididymis. (d) prostate gland. Mature Graafian follicle is generally present in the ovary of a healthy human female around stet. 5-8 days of menstrual cycle. 11-17days of menstrualcycle.

(a) (b) (c) 18-23 days of menstrual cycle. (d) 24-28 days of menstrual cycle. 29. Which among the following has 23 chromosomes?

[NCERT Exemplar, Q. 11, Pg 3) (b) Zygote Spermatogonia Secondary oocyte (d) Oogonia Choose the incorrect statement from the following In birds and mammals internal fertilisation takes place. Colostrum contains antibodies and nutrients. Polyspermy is prevented by the chemical changes in the egg surface, (d) In the human female implantation occurs almost seven days after fertilisation. (a) (c) 30, (a) (b) (c)

BJABSERTION &REASON;

Directlons for Questions Number 1-10 Each question consists of two statements, nanely, Assertion (A) and JReason (R).For selecting the correct answer, use be following code: (a) Both Assertion (A) and Reason (R) are the true and Reas Assertion (A). (R) is a correct explanation Reason (R) are the true but Reaso and (A) (b) Both Assertion a (R) Ís not correct explanation of Assertion (A). (c) Assertion (4) is true and Reason (R) is false. (d) Assertion (A) is false and Reason (R) is true, of

FMAN

REPRODUCTION

31

(AF Leyg cefls synthesise and secrete male .ASerin esticuar hormotes called androgens Rezsaa (RE

Andrvgens.

stimulte the process of [CUET 2022|

spematogenesS Assertio (A) Spermatogenesisoccurs in the seminiferous ubules of the testes Reason (R): Sertoli cells play 2 crucial role in nurturing and supporting deveioptng spernatogenic cells. 1 Assertion (A): The menstrual ph2se is characterized by the breakdown of the endometrial lining of the uterus. Reason (R): Redoced LH leveis during the menstrual phase lead to corpus luteum degereration. 4 Assertion (A): The zona pellucida is a glycoprotein layer surTOunding the sperm ceil's piasma membrane. The zona peilucida plays a crucial role Reason sperm-egg recogiton 2nd binding during fertilization. Assertion (A): Paruiton refers to the process fertilisation in hurmans.

R:

in

of

Rezson (R: Parturition is initizted by the release of oxytocin froa the naternal piuitary gland. 6 Assertion (A: The primary male sex organs are the seminal vesicles Rezson R): Serminal vesicles produce and release androgens, inciuding testosterone. 1. Assertion (A): Ovulation marks the end of the menstrual cycle.

Reason (R): Ovulation is triggered by a surge in LH leveis, causing the relezse of a mature egg from the ovarian foilicie.

Assertion (A}: The zona pellucida is essential for protecting the sperm cell uring its journey through the female reproductive tract. Reason (R: The zora pellucida is a thick, gel-like substance that surronds the sperm's plasma membrane. 9. Assertion (A): The cospus luteum secretes progesterone during the hteal pase of the menstrual cycle. Rezson (R): Progesterone is essential for maintaining the thíckened endormetrial Iining of the uterus in preparation for potertíal embryo implantztion. 10. Assertion (A): Lactation refers to the process of delivering a fully developed fetus. Reason RY: Lactation begins during pregnancy when the mammary glads produce colostrum. 8.

gcoKETENCY/CASE-BASED QUESTIONS: Directions for questíon 15.

L Read the following passage and answer the given questions. She hurnan reproductíve system is a complex and intricately new Crzanised systern responsible for the formation of organs sex in secondary and primary It drvicuals. cornprises organs play pivotal roles in the fermales, These and males bth RoCesses of gametogenesis and reproductive function.

Reprodecttve

Male

Female

Proces Prismary Sex

Orzats

Secordary

Sex

Testes

Ovaries

Epididyrnis, vas deferens, ejaculatory uct, accessory glands,

Fallopian tubes, uterus, cervix, vagina, mammary glands

penis

Gametogenesis Site Gametogenesis Process

Testes

Ovaries

Spermatogenesis

Oogenesis

Hormones Regulating Process

Testosterone, FSH, LH

Estrogen, Progesterone, FSH, LH

1.

Which organ is responsible for the production of ova (eggs) in females?

(a) Testes

(c) 2. (a) (b) (c) (d) 3.

(a) (b) (c)

(d) 4.

(a) (c)

5.

(a) (b) (c)

(d) IIL

(b) Ovaries Epididymis (d) Uterus What is the primary function of the epididymis in males? Sperm production Hormone secretion Sperm maturation and storage Uterine lining development Which of the following hormones is responsible for initiating ovulation in females? Testosterone Estrogen Progesterone Luteinizing hormone (LH) In the process of spermatogenesis, what is the end product that is eventually released from the seminiferous tubules? (b) Spermatocytes Spermatogonia Spermatids (d) Spermatozoa What is the primary role of the zona pellucida in the structure of the ovum? It contains the genetic material (DNA) of the ovum. It provides energy for the initial stages of embryonic development. It acts as a selectively permeable barrier. Itplays a critical role in sperm-egg recognition and binding uring fertilization.

Read the following passage and answer the question

6-10. Read the following passage and answer the given questions. Fertilisation is a complex process that culminates in the fusion of a sperm cell with an ovum (egg) to form a zygote. During sexual intercourse, semen is ejaculated into the vagina, and spermatozoa embark on a rapid journey through the female reproductive tract, with the destination typically being the ampullary-isthmic junction of the fallopian tube, where fertilisation occurs. The sperm head, which houses the nucleus carrying genetic material, is equipped with an acrosome containing enzymes that assist in penetrating the egg's protective layers. Once a sperm successfully penetrates the egg, a cortical reaction is triggered, preventing polyspermy by blocking the entry of additional sperm. This ensures that only one spern fertilises the egg, reducing the risk of genetic abnormalities. The fusion of the haploid sperm and ovum results in the formation of a diploid zygote, which undergoes mítotic divisions to develop intoa blastocyst. Subsequently, the blastocyst attaches itself to the uterine wall in a process called implantation, marking a critical step in establishing pregnancy and initiating the interaction between the developing embryo and the maternal body.

Oaal

32 6. Whais he prnay ole uring

of

the scrosome in a sperm cel

fetision?

(a) Enegy protuction (b} Penering the egg's protective layers (c) Hsgocic

material

mtotic ivisions War i he pOse of the corical reaction that occurs añ spem nters the egg?

(a} {3)

the egg's

Toise Toiite fiszton

se

Benie

Which structure of the spermn contains breaking down the egg's protective layers? (2) Nucleus (b) Midpiece (c) Tail (d) Acrosome What isthe outcome of the fusion between 9.

8.

enzymes

te

1a spemm and an

OVum?

Iating

(d

CUET (UG) Chapterwise Question

() Formation of a blastocyst b) Initiation of cortical reaction

(c) Release of enzymes

() Penetration of the uterine wall 10.

During which phase

of

the

menstrual cycle does

the typicaly undergo fertilisation? (b) Follicular phase (3) Menstrual phase (d) Luteal phase (c) Ovulatory phase

(c) To prevet poiyspemy

ovum

ANSWER KEY AJMULIPLECHOICE QUESTIONS (2)

LE2( 14(c)

124)

256)6(c)

21

7.6)

8.(a)

9.(2)10.

17.(2)

18. (b)

19. (2)20.

(b)

|29.(c)3Lic)

27.(2)28.

BASSERTION& REASON |Z(6)

|8. (c) QUESTIONS ICcoPEIENCYCASEBASED

L

(7(C)&()

LO2(c

9.(2)10. |9.a)

(b)

(b)

(c)

10. (c)

ANSWERS WITH EXPLANATION AHULTIPLE CHOICE QUESTIONE

Eglanaisr (A) Theist teaaica tezins aputerg ard is sot called Teo21se Puter maste bezinning tie reastual Sycle, tor mecçase in tie cesztcn of rersuaticn, of

E

te elezse of an af the e21 ra úe cvTy, a 23 ag cr in cyce, aprozímaety he 14 menstal Tis stateent

day

is

car

Crulatica

ually ccors in the midde

cycle Progetecte leveis re indeed a tieir highest

Curing this ghase.

(C Thís statement is incorrect

ccr, te corçus

f

ilistior does not

Luteurn, whích is formed from the

fotlicie zfer cvulaticn, will dezererzte. The deciine corps bteum canses in progeterore from he endometia! ining to brezk dowr ard result in

te

3. Option (d) is corret Eglanation: HCG Chuman piacertal lzcg)

chorionic ainmn nI ms relaxin nd crly áuring pregnancy wile Estrogen Te woman also. secretediinano-pregnant 4. Option (c) is corTect The blastocyst gets embedded in the Eplanation: endometium of E uterus. After attachment, the uterine cels divide rapidy cass the blastocyst to become embeddet nte cnein cf tie uterus. This leads to pregnancy 5. Optioa (b) is correct Eplanatiorr: The correct secuerce of the events in the fenale reprocuctive cycle is: D -Secreico ctFSHE-FSH leads to the growti of ovarian follicles into 2 flly mature Graafan follicle C-During the mid of menstrual cycle, there is sudden increzse in the level of LH (LH surge). A - LH surge leads to ovulstin B-Lis followed by Iuteal phase in which the remaining pars of te Gzafian follicle transform 2s the corpus luteum. T

aeetn

n

menstation D) This sztement is coTet Metopase s the raturzl cesszticn f menstruation ard reçrcdctive capacity in wCmet, zrd it typícally ccrs ndthe age of S0 in

6. Option (2) is correct Eplanation: The side efects of the use of anaboic sterois

2. Optson (d) in eorreet Explanation: Luteinizing kormone is ot secreted by the placenta ts primarily produced ard secreted by the anterior pítuitary glard in the train. Estrgen, progestogen, and humar chorionic zoradotrupin (hCG) are hormores that are indeed secreted ty the humar placenta during pregnancy.

brezst enlargement, etc 7. Option (b) is correct Esplanation: The fertilisation of the oum with sperm tais place in the ampulla region of the fallopian tube. As the g s reieased (a process called ovulation) it is captured by nge like projections of the end of the fallopian tubes (fimbrize a Ihe fimbriae sweep the egg into the tube. Clitoris, is sm. meet minora two labia sensitive protrusion, where

humars beings.

in males ínchsde prermature baldness, increased aggressiveness

1

UNAN

REPRODUCTION

33

Sal canal nasves through th cervix (he lower cnd of the b (uterus)) beljs the thahy to pass trom the wonmb into Thus, alou with vagina it is a bith canal (a) is correet Optlon & Eylanation: Ovulation is detinel as the pocess in which a mature (iraatlan follicle nuptures ant releases an ovum (0ocyte), correct 9. Optoa (a) ls

WinA

t

Eyplanation: Morula is a solid mass ofblastomeres, produced a series of cleavage divisious of the varly embryu, The enbryo with 8 to lo hlastoneres is called nouta. 10. Optlon (b) Is correet Eyplanation: Acrosonne is a special kind ot onganelle with a cAb-like structure that covers the anterior portion ofthe head of the spermatozoon and contains digestive cnrymes contains lytic enzymes that help in fertilization. Head is oval shaped and consists of a haploid mucleus and a cap like acrosome.

t

Middle piece is composed of axial filament surrounded by mitochondria and cytoplasm. Tail consists of a central axial

Alament. The sperm moves in fluid medium tract by the undulating movement of the tail,

of female genital

Optlon (c) Is correct Eyplanation: Ovum is spherical and is surrounded by four membranes: a. Plasma membrane (Oolemma), which is the innermost layer. b. Vitelline membrane, which is attached to the plasma membranc. c. Zona pcllucida. It is the transparent noncellular layer found outer to the Vitelline membrano. d. Corona radiata: It is the outer layer formed of follicle cells. These cells are bound together by hyaluronic acid. 12. Optlon (a) is correct Eyplanation: Oogenesis is initiated in cmbryonic stage when millions of egg mother cells (oogonia) are formed within cach foetal ovary. No morce oogonin are formed and added afler birth. These cells (Oogonia) undergo meiosis but get temporarily arrested at the prophase-l stage and are called primary oocytes, 13, Option (c) Is correct Explanation: Certainly, here's an explanation for cach of the correct statements: B. Second meiotic division in the secondary oocyte occurs in I1.

bls ovaryi This statement is correct. In the process of oogenesis, the second meiotic division in the secondary oocyte is arrested and does not complete until fertilisation occurs. The secondary oocyte is released trom the ovary during ovulation in an arrested state and will only complete the second meiotic

the

ifit is fertilised by a sperm cell. Fertilisation,of gametes occurs in the ampulla isthmic region of the oviduct: This statement is correct, Fertilisation typically occurs in the a ampulla of the oviduct (fallopian tube). After ovulation, if sperm cell successfully meets and penetrates the secondary 00cyte, fertilisation.occurs in the ampulla region of the oviduct before the newly formed zygote moves toward the uterus for implantation. Myometrium helps in muscular contractions of the uterus: This statement is correct, The myometrium is the middle layer of the uterine wall, and its main flunction is to contract during abor and menstruatio, These contractions are responsible for pushing the fetus out during childbirth and for expelling the nenstrual blood during menstruation. division D,

E

Opton (e) lr corrvet. Byanaion: Ihe menstealuyele is tetulated by the woontinatt nctions ot the hypothalanus, pituitaty, ovaries, 14.

and cndouettiunn. lypothalans causes the neatby pituitary gland to jnuee cetain chennicals, which prompt the ovaries to produe the sex lomenes 0cstrvgen nd progesterone. I5, Optlon (b) s coret. Eylanatiow: Ampulla is a part of Fallopian tube where fertilisatinovcurs. Fallopian tube is art of femalereproductive Nystem. 16. Option

(b) is correct.

Bylanation: Iostate gland

is the art of male reproductive systenn that is located just be low the bladder, Small and watnut shaped, the prustate surrounds the beginning of the urethra. 17.

Option (a) is correct.

Eplanation: Corona radiata is the innemost layer of thc cells of the cumulus oophous and is directly adjacent to the zona pellucida, the outer protective glycoprotein layer of the ovum. Zona radiata is a striated nmembrane situated next the yolk an of ovum. an extra embryonie foctal membrane which Chorion is is responsible for the formation of placenta. 18, Option (b) is correct. Eplanation: Oxytocin is produced in the hypothalamus and is sccreted by the posterior pituitary gland. It causes contraction

during parturition and help to brings baby out from the mother womb. 19, Option (a) is correct.

Eyplanation: Acrosomal reaction of the sperm occurs due to its contact with zona pellida of the ova. The reaction that occurs in acrosome of sperm is triggered by the release of fertilizin, The main purpose of the acrosomal reaction is to start the fusion of the oocyte membrane with the sperm cell membrane allowing the combination of genetic material contained in both gametes, leading to the fertilisation of the oocyte. 20. Option (b) is correct

Evplanation: Secretion of seminal vesicle (paired), prostate gland (unpaired) and bulbo-urethral glands or Cowper's glands (paired) constitute the seminal plasma,. It contains various proteins and ructose as encrgy suppliers for sperm motility and is also responsible for making the largest proportion of the alkaline buffer. 21. Option (d) is correct Explanation: Rete testis, vasa efferentia and epididymis are parts of male reproductive system. Whereas isthmus is part of Fallopian tube which carries an cgg from the ovary to the uterus. 22. Option (b) is correct

Eplanation: The vas deferens receives duct from the seminal

vesicle and opens into urethra as ejaculatory duct. These cjaculatory ducts which open into the urethra about half-way through the prostate gland function to mix the sperm stored in the ampulla with fluids secreted by the seminal vesicles and to transport these substances to the prostute. 23. Option (c) is correct Eyplanation: Urethral meatus, also known as the external urethral orifice, is the cxternal opening or meatus of the urethra. The urethra originates from the urinary bladder and extends through the penis to its external opening called urethral meatus.

Oswaal CUET (UG) Chapterwise Question Bank BIOLOA

34

Option (a) is correct. Eplanation: Spermatogenesis indeed occursintthe seminifetrs tubules of the testes, and Sertoli cells are crucial

2.

correct 24. Option (a) is

isthmus and ampulla Fimbriae, infundibulum' while labia minora is female are the parts of Fallopian duct extemal genitalia.

Elanation:

for

and supporting developing spermatogenic cells, making (R) an appropriate explanation for Assertion (A).

25. Option (b) is correct

high level of oestrogen Explanation: (a) Rapid secretion of sunge. (b) Oogenesis is initiated and LH triggers the ovulatory a couple developmental stage when during the embryonic egg at puberty starts spem formation that of million Unlike are formed more oogonia formation begins before birth. No from seminiferous released Sperms (c) and added after birth. They undergo physical tubules are poorly motile non-motile. and acquire increased maturation in the head of epididymis Progesterone level is high motility and fertilising capacity. (d) menstrual cycle because during the postovulatory phase of part of Graafian follicle becomes after ovulation the remaining corpus luteum. Corpus luteum a temporary endocrine gland, the pregnancy. secretes progesterone hormone to maintain

26. Option (c) is correct chromosomes and Erpianation: (a) Spermatogonia have 46 Primary spermatocytes alwzys undergo mitotic cell division. (b) Spermatids are transformed divide by meiotic cell division. (d) into spermatozoa. 27.Option (a) is correct process by which mature Erplanation: Spermiation is the from sertoli cells into are released spermatids or spermatozoa to their passage to the lumen prior the seminiferous tubule epididymis. 28. Option (b) is correct stage Eplanation: Mature Graafian follicle is the follicular first completion of ovary. the after It formed is present in the contains It therefore ovulation. before but mitotic division a a 2N diploid oocyte. Graafian follicle is characterised by ova or more one into large fotlicular antrum and releases

corpus luteum. It the Fallopian tube and leaving behind the a ovary present in the of healthy human female is generally round 11-17 days of menstrual cycle.

29.Option (c) is correct Erplanation: Secondary oocyte (n = 23). Primary oocyte completes fist meiotic division to fom secondary oocyte (23 chromosomes) and polar body (23 chromosomes), whereas spermatogonia, zygote and oogonia have 46 chromosomes, hence diploid.

30, Option (c) is correct Explanation: Polyspermy may be defîned as the fertilisation of an ovum by more than one sperm. During fertilisation, a sperm comes in contact with the zona pellucida layer of the ovum and induces changes in the membrane that block the entry of additional sperms. Thus, it ensures that only one sperm can fertilise an ovum.

B. ASSERTION

AND REASON QUESTIONS:

Option (a) is correct. Explanation: LH acts on the Leydig cells and stimulates synthesis and secretion of androgens. This happens at the age of puberty due to significant increase in the secretion of gonadotropin releasing hormone there is an increase in the secretion of gonadotropins i.e., LH and FSH. 1.

Ret

Option (a) is correct. Explanation: The menstrual phase is indeedcharacterizedty the breakdown of the endometrial lining, and reduced LH ie during this phase contribute to corpus luteum degenertn making Reason (R) a valid explanation for Assertion (A) 4. Option (c) is correct. 3.

Explanation: The zona pellucida surrounds the ovum the sperm cell's plasma membrane. While Reason(eg is correct regarding its role in sperm-egg recognitio. inaccurately describes the zona pellucida's location. not

(b) is correct. Explanation: Assertion (A) is incorrect because parturite refers to the process of delivering a fully developed fetus. fertilization. Reason (R) is true as oxytocin does play a rolei initiating uterine contractions during parturition, but it does prt explain Assertion (A) accurately. 6. Option (c) is correct. Explanation: The primary male sex organs are the testes not the seminal vesicles. Seminal vesicles do not produce androgens; instead, they contribute to seminal plasma. 7. Option (b) is correct. Explanation: Assertion (A) is not entirely accurate, as the menstrual cycle consists of multiple phases, and ovulation occurs within the cycle. However, Reason (R) comecty it describes the process of ovulation but does not explain whv marks the end of the menstrual cycle. 8. Option (c) is correct. (R) Explanation: While Assertion (A) is correct, Reason the as zona surounding pellucida inaccurately describes the the zona surrounds pellucida The membrane. sperm's plasma fertilizaticn ovum (egg) and plays a role in protecting it during 9. Option (a) is correct. are both accurzte Eyplanation: Assertion (A) and Reason (R) progesterone during the secrete corpus luteum does The maintaining the for crucial progesterone luteal phase, and endometrial lining for potential embryo implantation. 10. Option (d) is correct. as lactaticn ds Explanation: Assertion (A) is incorect, a fetus but rather to the process delivering of not refer to the mammary glands production and secretion of milk by the pregnany 5. Option

Reason (R) is true, as lactation indeed begins during when colostrum is produced.

[C| 1.

COMPETENCYICASE-BASEDQUESTIONS:

Option (b)

is

correct.

productioa planation: The ovaries are responsible for the ova (eggs) in females. 2. Option (c) is correct.

Eplanation: The primary function of the

epididymis

in

malo

is to store and mature sperm. 3. Option (d) is correct. initiating ovulation the Erplanation: LH is responsible for from mature Cgg females, specifically the release ovarian follicle. of

a

HUMAN

REPRODUCTION

4. Option (d) is

35

correct,

Eyplanation: Spermatozoa, also known as sperm cells, are the end product of spermatogenesis and are eventually released from the seminiferous tubules. 5. Option (d) is correct.

Eplanation: The zona pellucida is an extracellular matrix surrounding the ovum's plasma membrane, and it is essential for sperm-egg recognition and binding during fertilization.

Option (b) is correct. Elanation: The acrosome of a spermn contains enzymes that assist in penetrating the egg's protective layers during

6.

fertilization.

Option (c) is correct. Explanation: The cortical reaction's primary purpose is to prevent polyspermy, the entry of multiple sperm into the egg. ensuring only one sperm fertilizes it. 7.

8. Option (d) is correct.

Explanation: The acrosome is the structure in the sperm that contains enzymes necessary for breaking down the outer layers of the egg, allowing the sperm to penetrate it. 9. Option (a) is correct. Explanation: The fusion of a sperm and an ovum results in the

formation of a diploid zygote, which then undergoes mitotic divisions to develop into a blastocyst. 10. Option (c) is correct. Explanation: Fertilization typically occurs during the ovulatory phase of the menstrual cycle when a mature egg (secondary oocyte) is released from the ovarian follicle and is ready for fertilization in the fallopian tube.

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CHAPTER

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Time: 1:5 Hours Questions: 50

REPRODUCTIVE HEALTH It is well known that fertility in women decreases with increasing age, as showed by the following statistics: o Infertility in married women ages 16-20 = 4 sor o Infertility in married women ages 35-40:=31.8% o Infertility in married women over the age of an = 70%. Louise Joy Brown (born 25 July 1978) is the worla. first baby to be conceived via IVF at Oldham and District General Hospital in Manchester, England. to parents Lesley and Peter Brown. > Harsha Chawla born on óth August 1986 is recorde as the India's first IVF baby. >

Revision Notes

simply refers to The term 'reproductive health' organs with normal functions. healthy reproductive Organisation), According to WHO (World Health a total well means the word 'reproductive health' being in all aspects of reproduction i.e., physical, emotional, behavioural and social. The world population was estimated to have reached. 6 billion as of December 2017.

Strategies of Reproductive Health Programmes: To ensure total reproductive health, several programmes like reproductive health programmes and family planning were started in 1951. > Consequences of Population Explosion: Poverty, unemployment, shortage of food, unhygienic residential problems, education conditions, problems, pollution, crime, excessive consumption of natural resources etc. > Amniotic fluid is a clear, slightly yellowish liquid

that surrounds the unborn baby (foetus) during pregnancy. It is contained in the amniotic sac. > Insemination is a process of introducing semen into the reproductive tract of a female, either through sexual intercourse or with the help of syringe in the process known as artificial insemination.

> Ejaculation is the action of ejecting semen from the body.

> Dr. Gregory Goodwin Pincus was the first to discover birth control pills.

> The first Lippes Loop IUD was introduced in 1962. It was a plastic double "S" loop, a trapezoid-shaped IUD that closely fit around the contours of the uterine cavity, reducing the incidence of expulsion. > IUDs are currently the most effective long- acting, reversible birth control option available. The least effective methods of birth control are spermicides and withdrawal. Women are less likely to have symptoms common of STDs, such as chlamydia and

gonorrhoea, compared

O men. Human papillomavirus (HPV) is the most conmon STD in women and is the main cause of cerv1cal cancer.

> Artificial Insemination (A) technique: o The semen collected from the husband or a healthy

donor is artificially introduced into the vagina or the uterus (IUI- intra-uterine insemination) of the se female. o This technique is useful for the male partner having an inability to inseminate female or low sperm counts. Surrogacy- In this technique a woman (surrogate mother) bears a child for a couple unable to produce children, because the wife is infertile or unable to carry. The surrogate is impregnated either through artificial insemination or through the implantation of an embryo produced by in vitro fertilization. > Zygote Intra Fallopian Transfer (ZIFT): Transfer of zygote or early embryos (with upto 8 blastomeres) into the fallopian tube. Intra Uterine Transfer (1UT): Transfer of embryos with more than 8 blastomeres into the uterus. The embryo formed by in vivo fertilization (fertilization within the female) is also used for such transfer to assist those females who cannot conceive. Gamete Intra Fallopian Transfer (GIFT): Transie o of an ovum from a donor into the fallopian tube another female who cannot produce ovum, bud ano provide a suitable environment for fertilization development. (1CSI): Intra Cytoplasmic Sperm Injectionsperm (ro a single in whicha procedure laboratory (from

egg partner) is injected directly into an implanted female partner). Then the fertilized egg is into the woman's uterus. male

pregnancy

both.

or

pregnancies,

foetus

pregnancies. reproductive

of (PID),

pain,

continuation

causes Injection)

or

TIransfer)

mother

slightregion.

Transfer)

and

diseases ectopic

Insemination)

unwanted

Sperm

the

illegally

discharge,

genital births,

of

where

Insemination)

Transfer)

Fallopian

amniocentesis.

to

cancer

inflammatory

Fallopian

the

implantation

Cytoplasmic progesterone

harmful

avoid cases

the fluid

performed

still

in

Intra

or To In

abortions,

swellings

infertility

•

Itching,

•

Pelvic

Uterine

Uterine

Intra estrogen.

is

(Artificial

(Zygote

are of

tract.

(Gamete

-

(Intra

(Intra

preventsblastula.

(Intra

Contains

misuse

They Importance

and

•

•

onl ZIFT

ICSI

IUT

temale

GTFT

roblens

IUI

by

Symptoms

etc.

(ART)

I

herpes Syphilis, pregnancy

loop)

Ísed

Reproductive

termination

(MTP)

of It •

•

Lippes

Technologies

B

CuT,

(e.g., LNG-20)

(e.g.,

Hepatitis

IUDs

Genital Medical

Assisted

IUDs

Contraceptives

HIV,

IUDs

375) releasing

of dorcuitvRepoe

•

Progestasert,

releasing Non-medicated

Multiload

Examples Hormone

Oral

STDS

•Copper

Health transmitted

Cu7,

(e-g.,

•

sexual intercourse.

Preventions

Control

Cervical

Diseases

through

creams,

Methods

Barrie

Amniocentesis

Level

foams.

Condoms

vaults. -Third

Birth •Spermicidal

Diaphragm,

Natur and

of

syringes. Surgical

caps

•Use

partners/

application

and Map jellies

Level

Mind

pplication

Second

Definition

and unknown

interruptus

needles

condoms.

Abstinence

the

Che

Level

Positive

Negative

Lactational

Males)

partners.

Females)

First

Periodic,

sterilised

with

Trace

amen

Coitus

use

sex

(in

congenital disorder

multiple reproductive

Always

Avoid

aborted.

•Using

foeticides.

in

Vasectomy

(in

well-being

of

days metabolic

•

does period.

contraception.

Tubectomy

sex and

the birth

then

reproduction.

cycle.

detect before

is

WHO,

detect

to

Misused

female

any

•

reliable

of

a

to or

foetus.

of

Withdrawal

to of According

very before

It

in

10-17

•Not

health

all

Avoiding

of

aspects

helps disease

the •

menstural

ejaculation.

total

means

child

predicted.

lactation

coitus

foetus

Increased

ovulation

from

penis female

is fertilisation

any

of high.

and

method

exactly

during Menstruation

Chances

be

very

occur Natural

Cannot

•

not •

•

•

Oswaal CUET

38

(UG) Chapterwise Question Bank

BIOLOGY

OBJECTIVETYPE QUESTIONS From the sexually transmitted discases mentioned below, identify the one which does not specifically affect the INCERT Exemplar, Q.9, Pg. sex organs. 25 (b) AIDS (a) Syphilis (d) Genital warts (c) Gonorrhoca 10. Choose the correct statement regarding the INCERT Exemplar, Q. 11, Pg.7I procedure. 261 a are transferred (a) Ova collected from female donor to the Fallopian tube to facilitate zygote formation. (b) Zygote is collected froma female donor andtransferred,. the Fallopian tube. (c) Zygote is collected from a female donor and transferred t the uterus. (a) Ova collected from a female donor and transferred to the uterus. 11. Match List-I with List-II. [CUET 2023| List-II List-I (a) Lippes loop () Barrier (II) Hormone releasing device (b) Vaults (III) Non medicated IUDS (c) Periodic abstinence (IV) Natural method (d) Progestasert answer correct from the options given below: Choose the (a) (a)-(), (b)-(II), (c)-(IV), (d)-(II) (b) (a)-(1II), (b)-(1I), (c)-(IV), (d)-(I) (c) (a)-(III), (b)-(T), (c)-(IV), (d)-(II) (d) (a)-(1II), (b)-(), (c)-(I), (d)-(IV) 12. Identify the terminal method used to prevent pregnancy is:

9.

[AJMULTIPLE

CHOoICE QUESTIONS

Increased IMR and decreased MMR in a population will 24] INCERT Exemplar, Q. 2, Pg. cause rapid increase in growth rate. result in decline in growth rate. not cause significant change in growth rate. result in an explosive population/exp. to build up a reproductively A national level approach up in our country in was taken healthy society NCERT Exemplar, Q.5, Pg. 25]

1.

(a)

(b) (C)

(d) 2.

(b) 1960s. 1990s. (d) 1980s. generally conceive due not do mothers Intensely lactating Exemplar, Q.3, Pg. 24] [NCERT to the suppression of gonadotropins. hyper-secretion of gonadotrophins. suppression of gametic transport. suppression of fertilisation. are effective if used within Emergency contraceptives [NCERT Exemplar, Q. 6, Pg. 25]

(a) 1950s. (c)

3. (a) (b) (c)

(d) 4.

(a) 72 hrs of coitus. (b) 72 hrs of ovulation. (c) 72 hrs of menstruation. (d) 72 hrs of implantation. by the 5. Diaphragms are contraceptive devices used females. Choose the correct option from the statements [NCERT Exemplar, Q. 13, Pg. 26] given below. () They are introduced into the uterus. (ü) They are placed to cover the cervical region. (üi) They act as physical barriers for sperm entry. (iv) They act as spermicidal agents. (2) iand ii (c) ii and iii 6. Condoms are one

(b)

iand iii

(d) ii and iv of the most popular contraceptives because of the following reasons. [NCERT Exemplar, Q. 10, Pg. 25] (a) These are effective barriers for insemination. (b) They do not interfere with coital act. (c) These help in reducing the risk of STDS. (d) All of the above 7.

(a) (b) (c) (d) 8.

Choose the right one amongst the statements given below.

[NCERT Exemplar, Q. 7, Pg. 25] IUDs are generally inserted by the user herself. TUDs increase phagocytosis reaction in the uterus. IUDs suppress gametogenesis. IUDs once inserted need not to be replaced. Following statements are given regarding MTP. Choose the correct options given below.

[NCERT Exemplar, Q.2, Pg. 25] 0) MTPs are generally advised during first trimester.

(i) MTPs are used as a contraceptive method. (ii) MTPs are always surgical.

(iv) MTPs require the assistance ofqualifiedmedical personnel. (a) ii and iii iand ii (b) (c) iand iv

(d)

i

and ii

[CUET 2023] (a) Lactational amenorrhea (b) Sterilisation (c) Intra Uterine Device (d) Periódic abstinence 13. Transfer of an ovum collected from a donor into fallopian method. tube is called (b) ICST (a) ZIFT (d) IVF (c) GIFT 14. Which of the following is INCORRECT statement?. [CUET 2022) sperm motility and ions increases Cu A. In IUD's, released

fertilising capacity of sperms. B. Multiload 375 is medicated IUD. C. Lippes loop is non-medicated IUD. D. LNG-20 is hormones releasing IUD. E. Vault is an IUD. Choose the correct answer from the options given below: (b) A & B only (a) A & E only C only (d) B& (c) B&D only a natural method of birtn 15. Which of the following is 2022) |CUET control? amenorrhea (b) Lactational (a) Condoms (d) Diaphragms (c) IUD a child as the male parui to produce 16. A couple is unable condition this 2022) has low sperm count. Infertility caused by (CUET can be treated using (b) AI (a) ZIFT (d) IUT (c) GIFT

REPRODUCTIVE

39 What is correct for test tube 2022] of ova and embryonic Fertilisation (a) development takes place in test tube Fertilisation of ova occurs in uterus while (b) the development takes place in test tube Fertilisation ofova occurs test (c) in tube whereas development of embryo occurs in uterus

baby?CUET

17.

i Unfertilised ova develops in test tube (a) (b) (c)

(d) 19.

(a)

The function of copperions in copper releasing IUD's: They suppress sperm motility and fertilising capacity of sperms. They inhibit gametogenesis They make uterus unsuitable for implantation They inhibit ovulation In case of a couple where the male is having a very low sperm count which technique will be suitable for fertilisation ? Intrauterine transfer

)

Gamete intra-cytoplasmic fallopian transfer Artificial Insemination (d) Intra-cytoplasmic sperm injection (4) Intra-cytoplasmic sperm injection (c)

20. Select the option including all sexually transmitted diseases. (a) Gonorhoea, Malaria, Genital herpes

AIDs, Malaria, Filaria Cancer, AIDS, Syphilis (d) Gonorrhoea, Syphilis, Genital herpes 21. In vitro fertilisation is a technique that involves transfer of which one of the following into the fallopian tube? (a) Embryo only up to 8 celled stage (b) Either zygote or early embryo up to 8 celled stage (c) Embryo of 32 celled stage

(b) (c)

() Zygote only 22. Artificial insemination means (a) Transfer

(b) (C)

(d) 23.

(a)

(0)

04t

of sperms of a healthy donor to

a test tube

containing ova ova Transfer of sperms of husband toa test tube containing a into Artificial introduction of sperms of healthy donor the vagina Introduction of sperms of healthy donor direct-ly into the ovary the ZIFT Choose the correct statement regarding procedure. are transferred to the Ova collected from a female donor Fallopian tube to facilitate zygote formation. and transferred to Zygote is collected fronma female donor

the Fallopian tube. a female donor and transferred to ) Ygote is collected from the uterus. a and transferTed to the () Ova collected from female donor uterus. 24. The correct as surgical procedure

in male is: (a) ovariectomy. (c) vasectomy.

a

contraceptive method

(b) hysterectomy. (d) castration.

25. In human adult females Oxytocin (a) stimulates pituitary to secrete vasopressin (b) causes strong uterine contractions during parturition (c) is secreted by anterior pituitary (d) stimulates growth of mammary glands. 26. An IUD recommended to promote the cervix hostility to [CUET 202 1] the sperms is: (b) Multiload-375 (a) Copper-T (d) Cu7 (c) LNG-20 27. An infertile couple was advised to undergo In-vitro fertilisation by the doctor. Out of the options given below, select the correct stage for transfer to the fallopian tube for successful results? (a) Zygote only (b) Zygote or early embryo upto 8 blastomeres (c) Embryos with more than 8 blastomeres (d) Blastocyst Stage 28. Given below are four contraceptive methods and their modes of action. Select the correct match: Method Mode of action (i) Ovum not able to reach Fallopian tube (a) Condom (ii) Prevents ovulation (b) Vasectomy (iii) Prevents sperm reaching the cervix (c) Pill (iv) Semen contains no sperms (d) Tubectomy (a) (a)-(i); (b)-(ii); (c)- (iii); (d)iv) (b) (a)-(i); (b)-(iii); (c)-(iii); (d) -() (c) (a)-(iii); (6)-(iv): (C)-(ii); (d)-) (d) (a)-iv); (b)-(i); (c)- (ii); (d) -ii) 29. Condoms are one of the most popular contraceptives because of the following reasons. (a) These are efective barriers for insemination.KteA (b) They do not interfere with coital act. (c) These help in reducing the risk of STDs. (d) Allof the above 30. The term Health' is defined in many ways. The most accurate definition of the health would be: (a) health is the state ofbody and mind in a balanced condition. (b) health is the reflection of a smiling face. (c) health is a state of complete physical, mental, and social

well-being. (d) health is the symbol of economic prosperity.

B)ASSERTION &REASON: Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as. reason (R) (a) Both assertion (A) and reason (R) are true and is the correct explanation of assertion. are true but reason (R) (b) Both assertion (A) and reason (R) is NOT the correct explanation of assertion. (A) is true but reason (R) is false. Assertion (c) reason (R) is true. (d) Assertion (A) is false and 1. Assertion (A): Lactational amenorrhoea, (absence of menstruation) is a temporary contraceptive method.

Oswaal CUET(UG) Chapterwise Question

40

2

2. (a)

4.

6.

7.

8.

infection in

a

Urethra

female suffering from

(c) Chlamydiasis

(d) Trichomoniasis. infectious 5. Syphilis disease caused by Trepone pallidum with 3 stages:

Reason (R): Oral pílls are very popularr contraceptives among the educated urban women. Assertion (A): Diaphragms are contraceptive devices used by the male. of Reason (R): These devices are made rubber that is used to cover the cervical region. Sexually Assertion (A): Very often persons suffering from go detection timely not do for (STD) Diseases Transmitted and proper treatment. Reason (R): Absence or less significant symptoms in the to the eariy stages of STDs and the social stigma attached

a) Infections painless ulcers on the genitals i)First b) Blindness, heart trouble, aortic impairment i) Secoa c) Skin lesions, hair loss, swollen joints ii)Third (a) a-I, b-II, c-III (b) a-I, b-III, c-II (c) a-III, b-I, c-II (d) a-II, B-III, c-I IL. Read the following passage and answer the questians 6-10 given below: Lactational amenorrhea, is also called as postparhm infertility. It occurs when a women is not menstruatine and fully breast feeding. It is a temporary family plannina method. It is a contraceptive method where the mother is informed and supported in how to use breast feeding for contraception. As breast feeding delays the return of a mother's ovulation (when the woman's ovary releases an

disease. Assertion (A): Vasectomy is a sterilisation procedure advised for females as a terminal method. vas deferens Reason (R): In vasectomy, a small part of the is rermoved or tied by blocking gamete transport therefore preventing conception. Assertion (A): Interstitial spaces outside the seminiferous tubule have blood vessels and sertoli cells. germ Reason (R): Sertoli cells provide nutrition to the

(a) Amniocentesis (b) ParturitionC

cells.

(c) Lactational amenorrhea

Assertion (A): Determining the sex of an unborn child followed by MTP is an illegal process.eA tb) a test to the practice Reason (R): Amniocentesis presence of genetic dísorder also. 10. Assertion (A): ICSI is an assisted reproductive technique. ovum Reason (R): In ICSI sperm is directly injected into S

to form the embryo in vitro.

through:.

(a) Handshake (b) Bloodcontact (c) Sexual contact (d) Both (b) and (c). 4. Which amongthe followinggSTDs iscaused by yaprotozz ? (a) Syphilis (b) Gonorrhoea

sperm injection (ICSI) Assertion (A): Intra cytoplasmic in vitro. embryo to develop technique is used sperm is directly Reason (R): In ICSI technique, the ovum. injected into the Assertion (A): Abortions could happen spontaneously

9.

chlarmydizi

(b) Ureters (d) Peritoneum.

AIDS is caused by HIV. HIV is transmitted

3.

too.

5.

Site of

(c) Cervix

week pill.

3.

Bank

BIOLD

on the fact that ovulation and Reason (R): It is based occur during the period of therefore the cycle do not intense lactation following parturition. as an improved form Assertion (A): Saheli is considered females. of contraceptive for human a preparation and is once a non-steroidal Reason (R): It is

6.

egg) and may make her infertile for six months A procedure misused for female foeticide is:

orsi

or more.

io tog bofaLtne

(d) Artificial insemination.

Lactational amenorrhea is due to action of which hormone: (a)) Prolactin induced inhibition of GnRH (b) Prolactin induced inhibition of FSH (c) Oxytocin induced inhibition of GnRH (d) Oxytocin induced inhibition of FSH 7.

What is the meaning of lactational amenorrhea?b (a) Absence of menstruation period. (b) Delay in ovulation during lactational are almost nil upto six monts (c) Chances of contraception 8.

ccOMPETENCY/CASE-BASED QUESTIONS: I.

i

Read the following passage and answer the 1-5 given below: The term sexually transmitted disease (STD) is applied to the group of diseases that spread by sexual contact. Some infections like hepatitis-B and HIV can spread by sharing injection needles, surgical instruments etc. Except for hepatitis-B, HIV ínfections, genital herpes, most of the STDS are completely curable if detected early and treated properly. Though all persons are vulnerable to these infections, their incidences are high ín the age group of 15-24 years.

I. Which among the following is a venerable disease, caused by a virus, whích also gets transmitted by blood contact ? (a) Gonorrhoea (b) Syphilis (c) Trichomoniasis (d) Hepatitis-B.

s

(d) 9.

following parturition. All

of

these5loy

h

effective: The only birth control that is 100%

(a) Abstinence (b) Natural family planing (©)

Birth Control

pillst

(d) Emergency contraceptive

tot:al

used following chemicals is 10. Which among the ? chemical methods for contraception Citric acid b) h (a) Lactic All of these. acid Boric (c)

acid7Eh

u

REPRODUCTIVE HEALTH

41

ANSWER KEY |A] MULTIPLE CHOICE QUESTIONS 1. (b)

2. (a)

3. (a)

4. (a) 14. (a)

15. (b)

21. (b)

22 (c)

13.(c) 23. (b)

5. (c)6.

11. (6)

12. (b)

24. (c)

1.(a)

2. (a)

3, (a)

4. (b) C

1.(d)

2. (c)

3. (d)

10. (b)

8. (c)

16. (b)

17. () 27. (6)

18. (a)

19. (a)

28. (c)

29. (d)

20. (c) 30. (a)

9. (6)

10. (b)

26. (c) ASSERTION& REASON

|8. (d) COMPETENCY/CASE-BASED QUESTIONS

4. (d)

(6)

7. (6)

25. (a)

[B]

|9.

(d)

5. (d)

6. (a)

7.()

5. (b)

6. (a)

7.(a)

8. (d)

9.()

10. (d)

ANSWERS WITH EXPLANATION IATMULTIPLE CHOICE QUESTIONS 1. Option (b) is correct Eyplanation: Both IMR (infant mortality rate) and MMR i (maternal mortality rate) are responsible for affecting the

growth rate inverscly. It means decline in IMR as well as MMR will result in high population growth and vice-versa. Hence, if there is an increased IMR and decreased MMR in a population mothers are there to give births to infants whereas the survival rate of infants becomes low. Therefore, in a particular population, increased IMR and decreased MMR will hinder their growth rate.

Option (a) is correct Eyplanation: A national level approach to build up a reproductively healthy society was taken up in India in 1950s. 3. Option (a) is correct Explanation: Breast-feeding is one of the temporary and natural contraceptive methods which reduce the secretion of oestrogen hormone and thereby suppress ovulation (release of egg) and cause amenorrhoea. The contraceptive efect of the lactational amenorrhoea method is a result of increased levels of prolactin. In this condition, production and secretion of gonadotrophin releasing hormones are inhibited and resulted in low secretion of oestrogen. As ovulation cannot occur without a surge in oestrogen levels, and ifa woman does not ovulate, pregnancy is prevented. 2.

Option (a) is correct Explanation: Emergency contraceptives are effective if they are used within 72 hours of coitus. They can prevent unwanted pregnancies after unprotected sex, failed used of contraceptive devices or due to rape, etc. Two types of emergency contraceptives include emergencies pills or IUDs. 4.

Option (c) is correct are Explanation: Diaphragms, cervical caps and vaults pregnancies. to avoid contraceptive devices used by females These devices are made of rubber that is introduced into the temale reproductive tract to cover the cervix during coitus. 5.

Spermicidal creams, jellies and foams are usually used along

these barriers to increase their contraceptive efficiency. ney block the entry of sperm through cervix and thereby prevent conception. They are reusable.

With

6.Option (d)

is

correct

Explanation: Condoms can both prevent pregnancy by Stopping sperm from meeting an egg. They also protect against Sexually-transmitted infections (STIS). Condoms act as a

up of very barrier method of contraception. They are made pregnancy are by prevent to designed and latex (rubber) thin not egg. interfere an do They sperm meeting from stopping with coital act. 7. Option (b) is correct Explanation: IUDs are of two types: copper IUD and hormonal IUD. Both types of IUDs work primarily by preventing sperm from reaching and fertilising an egg. The copper IUD releases spermicide and copper into the uterus, which works as suppresses the motility and fertilising ability of sperm whereas the other IUDs release progestin hormone into the uterus. The progestin thickens the cervical mucous so that sperm can't reach the egg.

8. Option (c) is correct Explanation: Medical termination of pregnancy is also called induced abortion. It cannot be used as a contraceptive method. MTP is done to get rid from unwanted pregnancies arises due to rape, genetic abnormalities in child, or when mother has somne risks by the developing child. MTP is safe up to first trimester of pregnancy, that is, 12 weeks. MTP done in the supervision of medical practitioner under some law 9. Option (b) is correct

Explanation: (b) Sexually transmitted diseases are transmitted through sexüal intercourse. They are also called as venereal diseases (VDs) or reproductive tract infections (RTI). Examples of STDs are syphilis, gonorrhoea, genital warts, trichomonas, AIDs, etc. In the above-mentioned diseases, AIDS does not affect any sex organ. It is a set of symptoms or illness that arises as a result of advanced HIV infection which has destroyed the immune system. 10. Option (b) is correct

Explanation: In zygote intra-Fallopian transfer, the zygote is collected from a female donor and placed in Fallopian tubes rather than directly in the uterus.ZIFT is the result of combining IVF and GIFT. 11. Option (b) is correct Explanation: List-II List-I (i) Non-medicated IUDs (A) Lippes loop (ii) Barrier (B) Vaults (iii) Natural method (C) Periodic abstinence (iv) Hormone releasing device (D) Progestasert

42 12. Option (b) is

Oswaal CUET (UG) Chapterwise Question EBank BIOLOGY

correct

Explanation: The terminal method of contraception means surgical methods. In males it is called vasectomy and in females is called tubectomy,due to this transport of gametes blocked. 13. Option (c) is correct Explanation: GIFT is the method in which transfer of ovum collected from a donor into the fallopian tube of another female who cannot produce one, but can provide suitable environment for fertilisation takes place. Whereas, ZLFT stands for Zygote intra fallopian transfer which involves transfer of zygote (upto 8 blastomeres) into the fallopian tube. ICSI stands for Intracytoplasmic sperm injection and is the method of injecting the sperms directly into the ovum in-vitro. IVF stands for in vitro fertilisation. 14. Option (a) is correct Explanation:. There are three different IUD types: () Non-medicated IUDS These devices, such as Lippes uterus. loops, promote the phagocytosis of sperm within the to phagocytosis of the addition (ii) Copper-releasing IUDs-In sperms, the released copper ions also inhibit sperm motility and sperm fertility. For example: Multiload-375, Cu-T, and Cu-7. (ii) Hormone-releasing IUDs, such as progestasert and LNG-20, render the uterus unsuitable for implantatio and the cervix hostile to sperm. Vaults are a type of barrier method which blocks the entry of sperm and prevents conception. 15. Option (b) is

correct

as Explanation: Lactational amenorrhea is also known means your body is making postpartum infertility Lactation breastmilk and amenorrhea refers to absence of monthly period in females. It is a method of natural contraception, which is based on the fact that the process 'of ovulation does not occur , 3 it sna during the period of intense lactation. 16. Option (b) is correct Explanation: Artificial insemination (A) technique is useful for the male partner having inability to inseminate female or has low sperm counts. It is the' method of transferring semen (sperm) collected from the husband or a healthy donor into the vagina or the uterus (1UI-intra-uterine insemination) of the recipient Female Zygote Intra Fallopian Transfer (ZIFT) involves transfer of zygote or early embryos (with up to 8 blastomeres) into fallopian tube. Gamete Intra Fallopian Transfer (GIFT) is the method of transfer of gamete (ovum) from a donor into the fallopian tube of another female who is unable to produce ovum, but can provide right conditions for fertilization and development of an embryo. Intra Uterine Transfer (IUT) involves transfer of embryos with more than 8 blastomeres into the uterus. The babies thus produced from this method are known as test tube babies. 17. Option (c) is correct. Explanation: Test tube baby is a term used to refer to a child that is conceived outside the women's body by a scientific process. The entire process is done in a laboratory. In this method, ova froa the wife/donor and sperms from the husband/donor are cottected and are fertilised to form zygote under simulated cqaditions in the laboratory. The fertilised ovum is then placed the uterus of a female.

Option(a) is correct. Explanation: Cu ions in Cu releasing IUDs suppresses sperm motility and fertilising capacity of sperm.

19.

Option (c)

is

correct.

Artificial insemination (AI) is a technique semen collected from the husband or a healthy in the donon artificially introduced either into the vagina or the uterus,

Explanation: which

is 20.

Option (c) is correct.

Explanation: Gonorrhoea caused by Neisseria gonorrhoeae. Syphilis caused by Treponema pallidum, GenitalI herpes caused

by HSV-2.

21. Option (b) is

correct.

Explanation: In vitro fertilisation, the zygote or early embryos 8 blastomeres is transferred into the fallopian

develop up to

tube. 22. Option (c) is

correct.

Explanation: In artificial insemination [AI] technique h semen collected either from the husband or a healthy donor i artificially introduced either into the vagina or into the utens (IUI-Intra Uterine Insemination) of the female. 23. Option (b) is

correct.

Explanation: In zygote intra-Fallopian transfer, the zygote is collected from a female donor and placed in Fallopian tubes rather than directly in the uterus. ZIFT is the result of combining IVF and GIFT. 24. Option (c) is correct.

Explanation: Vasectomy is the correct surgical procedure as a contraceptive method in male. During this procedure, vas deferens is cut down to prevent sperm from entering into female, the urethra and thereby preventing fertilisation. tubes is Fallopian this procedure called tubectomy in which are held and blocked or severed and sealed, either of which prevents eggs from reaching the uterus for implantation. Removal of ovary, uterus and testes are called as ovariectomy, hysterectomy and castration respectively. 25. Option (b) is correct.

Explanation: Oxytocin is produced in the hypothalamus and is secreted by the posterior pituitary gland. It causes contraction during parturition and help to brings baby out from the mother womb.

26. Option (c) is correct.

Explanation: Intra Uterine Devices (IUDs) presently available are: (A) The non-medicated IUDs e.g., Lippes loop. (B) Copper releasing IUDs e.g., CuT, Cu7, Multiload 375. () The hormone releasing IUDs e.g., LNG- 20 and Protesters. These IUDs increase phagocytosis of sperms within the uterus and the Cu ions released suppress sperm motility and the fertilising capacity of sperms. The hormone releasing IUDS, in addition,make the uterus unsuitable for implantation & the cervix hostile to the sperms. 27. Option (b) is correct. which

Explanation: In-vitro fertilisation the technique in the fertilisation takes place outside the body but the condtio are similar as that present in the body. Fertilisation process 1 process the zygote o Tollowed by embryo transfer (ET). In this are transferred ino early embryos (with up to 8 blastomeres) the fallopian tube.

REPRODUCTIVE HEALTH

43

Option(c) is correct.

8

Eanation: thin

in

rubber or

vagina and cervix in the female. method which prevent the physical

male or

humer

Condoms are barriers, which are made up of latex sheath. They are used to cover

is

the penis is a type of

meeting of ovum

surgical intervention, which blocks nd prevents transport thus conception. This sterilisation gamete rocedureinthe male is called vasectomy. In this a small part of prox is removed or tied up, as vas deferens where tubectomy, the the fallopian tube is removed orin up. small part of tied Pills a doses feither progestogens or progestogen are small estrogen combination,,used orally by females in the form of tablets sperms, Vasectomy

of

29.

Option (d) is correct.

Condoms can both prevent pregnancy by sperm meeting an egg. They also protect from stopping against serually-transmitted infections (STIs). Condoms act as a method of contraception. They are made up of very barrier (rubber) and are designed to prevent pregnancy thin latex by from meeting an egg. They do not interfere sperm stopping Erplanation:

with coital act. 30.

Option (c) is correct.

Erolanation: Health may be defined as a person's mental and condition. It is a state of complete physical, mental

nhysical

nd social well-being and not merely the absence of disease or infrnity. When people are healthy, they are more efficient in their work. It also increases longevity of people and reduces infant and

maternal mortality.

Erplanation: 'Lactational amenorrhoea' means lack of mnenses resulting from breast-feeding. During this period high level of prolactin and a reduction of gonadotropin-releasing hormone 2.

the hypothalamus suppress ovulation.

Option (a) is correct.

Explanation: 'Saheli' is considered as an improved form of contractive for a human female because: () it is non-steroidal or no side effects. (ii) it has a high it preparation.

(i)

has lesser

contraceptive value. (iv) It is 3.

Option (d) is correct. in the male Eplanation: Vasectomy is a sterilisation procedure a vasectomy, In tubectomy. is called while that in the female up or through tied stnall part of the vas deferens is removed a small a small incision on the scrotum while in tubectomy a small up or through tied is removed part of the fallopian tube incision in the abdomen or through vagina.

7.

Option (d) is correct. Explanation: The interstitial spaces are the regions outside and the seminiferous tubules, contains small blood vessels interstitial cells or Leydig cells. Each seminiferous tubule germ is lined on its inside by two types of cells called male provide cells Sertoli cells (spermatogonia) and Sertoli cells. nutrition to the germ cells during spermatogenesis. 9. Option (b) is correct of child followed Explanation: Determining the sex an unborn , process is a amniocentesis an in India illegal by MTP is of technique to test the presence genetic disorder also. 8.

10. Option (b) is correct Explanation: 1CSI is an assisted reproductive technique in this process sperm is directly injected into ovum to form the

embryo in vitro

BASSERTION& REASONQUESTIONS. 1. Option (a) is correct.

from

Option (a) is correct. symptoms in the early Erplanation: Absence or less significant attached to the STDs stigma stages of infection and the social persons for timely detection going from deter the infected inflammatory diseases to pelvic leading treatment proper and infertility or (PID), abortions, still births, ectopic pregnancies, even cancer of the reproductive tract.

6.

once a week pill.

Option (a) is correct.

Erplanation: In infertility cases artificial insemination (AI) techniques are used to cure the patient.

Option (b) is correct. Lplanation: When the fertilisation become successful than some Womarn become pregnant but it become terminated is or e not planned didn't intentionally if she is unmarried or babies in some case. abortion happen accidentally Degligence in case of pregnant mother. S. Option (d) is correct.

4.

c

nation: Diaphragms are contraceptive devices used by are made of the females to avoid pregnancies. These devices tabber that is introduced into the female reproductive tract to Cover the cervix during coitus. They act as physical barriers for pem entry.

[C| COMPETENCYICASE-BASED QUESTIONS: I. 1. Option (d) is correct. Erplanation: Hepatitis B is a serious infection of the liver caused by a vinus. Symptoms may include tiredness, loss of appetite, stomach discomfort and yellow skin. The virus is found in blood, semen, vaginal fuids and saliva. Hepatitis B is the only sexually transmitted disease that has a safe and effective vaccine to protect against infection. 2. Option (c) is correct. Explanation: The most common manifestation of chlamydia infection is infection of the cervix with inflammation (cervicitis) in women.

3. Option (d) is correct. Explanation: HIV is transmitted through the exchange of certain types of bodily fuids including: blood, semen, breast milk, and vaginal fuids 4. Option (d) is correct. Eplanation: Trichomonas is a very common sexually transmitted disease (STD). is caused by infection with a protozoan parasite called Trichomonas vaginalis. 5. Option (b) is correct. Explanation: A person with first stage of syphilis generally has a sore or sores at the original site of infection. These sores usualy occur on or around the genitals. These sores are usually (but not always) firm, round, and painless. Symptoms of secondary syphilis include skin rash, swollen lymph nodes., and fever. Tertiary syphilis is associated with severe medical problems. It can affect the heart, brain, and other organs ofthe body.

Oswaal

CUET (UG) Chapterwise

44 Option (a) is correct. sex Explanation: Amniocentesis is the technique of embryo in pregnancy using amniotic fuid determination

II. 6.

of

from mothers

womb.0

Option (d) is correct.

8.

Explanation: After giving birth to the child, women l2ctates for feeding baby and there is no chances fertilisaucn i till 6 months. milk

of

Option (a) is correct. is Explanation: Abstinence the prevention of birh control by fertilisationnof egg withspem. eliminating all the chances 10. Option (d) is correct 9.

Option (a) is correct. is a result of Explanation: The lactational amenorrhea and of prolactin. In this condition, production 7.

increased level hormone (GnRH) from secretion of Gonadotrophin releasing which results in low secretion of the hypothalamus is inhibited cannot occur without luteinising hormone (LH). An ovulation a surge

Question Bank

of

Explanation: Lactic acid, boric acid and citric acid all ars as chemical contraceptive methods.

of LH.

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supergradscUET 16.8L STUDENTS FOR CUET'24

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203

TINIT II: Genetics

and Evolution Study Time

CHAPTER

5

Max.

'

Heredity: o Heredity, derived from the Latin word "hereditas," refers to the transfer of specific characteristics from parents to offspring.

It encompasses all biological processes responsible for passing on traits, whether through asexual or sexual reproduction.

Variation: o Variation pertains to the natural tendency for differences to exist among the traits ofindividuals withina progeny.

o These differences can manifest as distinctions between off'spring and thei parents, highlighting the diversity within a population. Scan to know more about Mendel's Laws of Inheritance this topic o Gregor Mendel conducted groundbreaking hybridisation experiments On garden peas from 1856 to 1863, leading to Laws the formulation of the laws of Mendel's - Inheritance inheritance. Trait Studied Seed Colour Seed Texture

|Contrasting Traits Yellow vs. Green Smooth vs. Wrinkled

Purple vs. White |Flower Colour |Axial vs. Terminal Flower Position Green vs. Yellow Pod Colour Pod Shape |Inflated vs. Constricted Stem Length |Long vs. Short These traits were instrumental in Mendel's development of the principles of heredity and the laws of inheritance.

o Collect pollen grains from the other plant (male parent) and transfer them to the flower of female parent for pollination.

o Collect seeds produced by the female parent, which represent the offspring.

o Mendel made similar observations for other pairs of traits and proposed that these traits are due to inherited

"factors" which were later called genes. The F, generation (Tt) produces gametes T (allele for tall stem) and t (allele for short stenm) in equal proportion when self-pollinated. o Mendel self-pollinated the F2 generation plants and found that dwarfF, plants continued to generate dwarf plants in the Fz and F, generations. o He concluded that the genotype of the dwarfplants was homozygous (tt). Monohybrid Phenotypic Ratio: 3 Tall : 1Dwarf-3:1 Monohybrid Genotypic Ratio: 1 Homozygous tall (TT) :2 Heterozygous tall (Tt): 1 Homozygous dwarf (t) Back Cross and Test Cross: o A back cross involves the crossing of an F hybrid with either of its parent plants. o A test cross is the crossing of an F, hybrid with its recessive parent. It is used to determine the unknown genotype of the Fz generation. O

Mendel's Principles or Laws of Inheritance: Principle of Dominance:

o

o o

Monohybrid Cross: monohybrid cross involves two plants that difer in one pair of contrasting characters, typically controlled by a single gene. For example, Mendel crossed tall and dwarf pea plants to study the inheritance of a single gene goverming

O A

O

plant height. Steps in O

Making a cross of Pea:

Select two pea plants with contrasting characters, such

as tall and dwarf. O

Remove the anthers (emasculation) of one plant to prevent self-polination; this plant becomes the female parent.

Questions: 50

HEREDITY AND VARIATION

Revision Notes

o

Max.

Time: 1:5 Hours

o

o o o o

Characters are governed by discrete units known as factors (later called genes). These factors occur in pairs on homologous chromoSomes. In a dissimilar pair of factors (contrasting alleles), only one member of the pair (dominant allele) expresses its effect in the hybrid. The manifestation of the other allele (recessive allele) is masked in the presence of the dominant allele. Dominant alleles determine the observable traits (phenotype) in heterozygous individuals. Recessive alleles are only expressed when an individual is homozygous for the recessive allele. The dominance relationship is specific to each gene and its alleles. Mendel's experiments with pea plants demonstrated the principle of dominance and led to the formulation of this fundamental genetic concept.

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aEREDITNAND VARIATION

Principle of Dominance: consider the genc responsible for flower colour in a particular plant species. There are two alleles for this gene: "R" for red flowers Aominant) and "r" for white flowers (recessive). When a plant has two dominant alleles (RR), it will produce red flowers. Whenaplant hasone dominant allele and one recessive allele (Rr), it will also produce red flowers because the dominant allele (R) masks the effect of the recessive

47

Example of the Let us

allele (r).

o Only when a plant is homozygous

for the recessive allele (rr) it will produce white flowers. o In this example, the principle dominance of is illustrated hy the fact that the dominant allele (R) determines the fower colour (red) in both homozygous dominant (RR) and heterozygous (Rr) individuals, while the recessive allele (r) is only expressed in homozygous recessive (r) individuals, resulting in white flowers.

Law of Segregation: o Allelic pairs gene variants) segregate during gamete formation. o

Fach individual has two alleles for each gene, one inherited from each parent. o These alleles segregate into separate gametes during the formation of eggs and sperm.

o The segregation is random, meaning that each gamete receives one allele, and it is a matter of chance which allele is passed on. o Homozygous individuals have two identical alleles for a gene (e.g., RR or rr), and they produce gametes containing only one type of allele (R or r). o Heterozygous individuals have two different alleles for a gene (e.g., Rr), and they produce gametes with an or b equal chance of containing either allele (R r). o When fertilisation occurs, the alleles from the male and female gametes unite, restoring the diploid number of alleles in the offspring. o The Law of Segregation ensures genetic diversity in offspring and is a fundamental principle of Mendelian

oz

genetics.

Example of the Law of Segregation:nguioz 1. Parental Generation: pea plants: one O In the parental generation, there are two one with white With purple flowers (genotype PP) and flowers (genotype pP). identical dominant O The purple-flowered plant has two plant has two white-flowered alleles (PP), and the identical recessive alleles (pp). 2. Gamete Formation (Segregation): O During gamete formation in the purple-flowered plant for purple TP, it produces gametes with the allele flowers (P). O

Similarly, the white-flowered plant (pp) produces gametes with the allele for white flowers (p).

3.

o

Fertilisation (Random Union): When these ganetes unite through fertilisation, random

pairing occurs. The offspring inherit one allele from each parent. o Possible combinations include PP (homozygous dominant), Pp (heterozygous), and pp (homozygous recessive). 4.

Offispring Phenotypes:

o The resulting offspring may have the following phenotypes: • Homozygous Dominant (PP): Purple flowers. Heterozygous (Pp): Purple flowers (due to the dominance of the Pallele). • Homozygous Recessive (pp): White flowers. as alleles (P In this example, the Law of Segregation is evident gamete formation. and p) segregate into separate gametes during to the leads gametes fertilisation during The random union of inheritance of different combinations of alleles, resulting in varying flower colours in the offspring (purple or white).

Law of Independent Assortment: o It states that when more than one pair of contrasting

characters (genes) is involved in a cross, the segregation of one pair of contrasting characters is independent of the segregation of another pair of contrasting characters. o In other words, the inheritance of one trait does not influence the inheritance of another trait during gamete formation.

Key Points of the Law of Independent Assortment: 1. Multiple Gene Pairs: The law applies when considering the inheritance of traits governed by different gene pairs (genes located on different chromosomes). 2. Random Assortment: The segregation of alleles for one trait into gametes is independent of the segregation of alleles for another trait. It occurs randomly.

Dihybrid Cross: The law is most evident in dihybrid crosses, which involve the study of two pairs of alleles for two different traits simultaneously. 3.

Example of Law of Independent Assortment: Let us consider a dibybrid cross involving pea plants with two pairs of contrasting traits: seed colour and seed shape. o Trait 1 (Seed Colour): There are two alleles, "y" for yellow seeds (dominant) and y" for green seeds (recessive).

o Trait

2 (Seed Shape): There are two alleles, "R" for round seeds (dominant) and " for wrinkled seeds rs (recessive).

Cross Involving Seed Colour (Y/y) and Seed Shape (R/r): Parental Generation (P): ho Plant 1: Yellow seeds and round seeds (genotype: 9te YYRR)

o Plant

2: Green seeds and wrinkled seeds (genotype:

yyrr) Gamete Formation: o Each parent produces gametes (sperm and egg cells) with alleles for both traits. o Plant 1 (YYRR) produces gametes with alleles YR, YR, YR, and YR.

Oswaal CUET (UG) Chapterwise Question Bank BIOLOGY

48 o Plant 2 (yyrr) produces gametes with

2sae

and yr.it

a

2 (yyrr) produces gametes with alleles YR,Y yr and 1cl yR, o square to showthe possible combinations a Let's use Punnett's combine: gametes of alleles when these o

alleles yr, yt, yr,

3a

has YyRr genotype and yellow, is round seeds. This F, generation.: Fertilisation in F, generation (Punnett's Square): o Plant 1 (YYRR) produces gametes with alleles YR, Yr,

o Resultant progeny

Plant

Offspring Genotypes: shown inthe Punnett's square, there are possible combinations of alleles among the offspring.

o

As

l6

yR, and yr.

Dihybrid Cross

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Offspring Phenotypes: t o The genotypes lead to different phenotypes for seed colour and seed shape. o The phenotypic ratios among the offspring include various combinations of yellow/green seed colour and round/wrinkled seed shape. Phenotypic Ratio: o The phenotypic ratio among the offspring is typically 9:3:3:1, which means that the offspring exhibit four different combinations of phenotypes: 1. Yellow and round (YyRr): 9 individuals

o An example of incomplete dominance is seen in flower in Snapdragon (Antirrhinum sp.) and . (4 jalapa o'clock plant).

colour

Bxample 1: Snapdragon Flower Colour: are two alleles for colour: O In Snapdragon flowers, there ae"R" for red and "W" for white. hom0zygous O Homozygous RR plants have red flowers, KW WW plants have white flowers, but heterozygous i plants have pink flowers. offspring (RW)3 0 The phenotype of the heterozygous pare homozygous two intermediate between the phenotypes.

2. Yellow and wrinkled (Yyrr or YyRr): 3 individuals 3. Green and round (yyRr or YyRr): 3 individuals 4. Green and wrinkled (yyrr): lindividual

This dihybrid cross illustrates the Law of Independent Assortment, as the segregation of alleles for seed colour (Yly) occurs independently of the segregation of alleles for seed shape (R/). The offspring exhibit various combinations of genotypes and phenotypes, showcasing the independent assortment of these two pairs of contrasting traits.

Non-Mendelian Inheritance: (a) Incomplete Dominance:

o Incomplete dominance occurs when the heterozygous

offspring exhibit an intermediate phenotype that is a blend or mixture of the two parental characteristics.

Mirabilis

Example 2: 4 o'clock Plant Flower Colour: o In the 4 o'clock plant (Mirabilis jalapa), there white. "W"for alleles for flower colour: "R" for red and

ae

homozygous

O

Homozygous RR plants have red fiowers, heterozygous oftet WW plants have white flowers, and colour, plants have flowers of an intermediate described as pink or variegated.

(b) Co-dominance: o

Co-dominance occurs are expressed equally andindeependentlyin

without blending. Example: ABO Blood Grouping in Humans: o

gene

of a when both alleles a hybrt

by The ABO blood group is determined three alleles: IA, IB, and 1.

gene a

wiiá

HEREDITYY

AND

VARIATIONeef2t3 Ta5

49

Allele IA codes for theA antigen on the surface of red blood cells. Allele IB codes for theBantigen on the surface of red blood cells.

Alleleidoes not produce any antigen and is recessive. Individuals with two dominant alleles (1^IA or BB) express either or A B blood types, respectively. o Heterozygous individuals (1^I") express both A and B antigens equally, resulting in the AB blood type. o The co-dominance I^ and IB alleles leads to the of presence of both A and B antigens on the surface of red blood cells in AB blood type individuals. Multiple Allelism:

o Walter Sutton and Theodore Boveri further connected chromosome behaviour to Mendel's laws, proposing the chromosomal theory of inheritance. o The chromosomal theory revealed that chromosomes on and genes occur in pairs, with alleles located homologous sites.K o During meiosis, chromosomes segregate independently, similar to how genes assort independently.

o

(c)

Linkage and Recombination

o

o Multiple allelism occurs when more than two alleles govern same

the trait or character, but each individual has only two alleles. Example: ABO Blood Grouping o In the ABO blood group system, there are three alleles: IA, IB, and i. o [A and are co-dominant alleles, while i is recessive. o In a population, individuals can have combinations of these three alleles, leading to different blood types (A, B.AB, and O) based on the specific allele combinations present in an individual. (d)

Pleiotropy: 7

o Pleiotropy occurs when a single gene controls multiple, seemingly unrelated traits or characteristics. Example: Pea Plant Seed Texture and Starch Grain Size: o In Mendel's pea plants, there is a gene called "R" that controls both seed texture and starch grain size. o Homozygous RR plants have round sceds and large starch grains. o Homozygous plants have wrinkled seeds and small starch grains. o The same gene (R) affects both the texture of the seeds (round or wrinkled) and the size of starch grains (large or small). Pleiotropy in this case demonstrates that a single gene can have a broad influence on multiple traits or characteristics, even when those traits may seem unrelated at first glance. O It often involves the impact of a gene on multiple metabolic pathways.

r

Polygenic Inheritance: tidi O While Mendel studied traits with distinct alternate forms controlled by single genes, many traits exhibit continuous variation and are controlled by multiple genes. These are called polygenic traits. Polygenic traits involve additive effects of alleles from multiple genes. o Human traits like height and skin colour are classic examples of polygenic inheritance. 11

Sex Determination:

o In many organisms, sex determination is based on

1.

Chromosomal Theory of Inheritance: o Gregor Mendel published his groundbreaking work on inheritance in 1865, introducing the principles of heredity. o Unfortunately. Mendel's work remained largely unrecognised until 1900 due to limited communication, resistance to his gene concept, and the mathematical nature of his research. O In 1900, three scientists independently rediscovered Mendel's work, bringing his concepts to the forefront of genetics. O Advances in microscopy allowed scientists to observe cell division and discover chromosomes, providing a critical link between Mendel's laws and physical structures.

Scan to know

Thomas Hunt Morgan's research more about on Drosophila (fruit fies) involved this topic dihybrid crosses. 0 Morgan observed that genes on the same chromosome could be linked, deviating from the expected Linkage, Recombination 9:3:3:1 phenotypic ratio predicted by Mendel. o The termslinkage" and recombination" were introduced to describe the physical association of genes on a chromosome and the generation of non-parental gene combinations. o Some genes on the same chromosome are tightly linked (low recombination), while others are loosely linked recombination). (high ti o Genetic maps, based on recombination frequencies, were developed to help determine the relative positions of genes on chromosomes. 2

2.

3.

differences in sex chromosomes. Sex Determination in Humans: o Human sex determination is based on the presence of X or Y chromosomes. o Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). Sex Determination in birds: o Birds, sex determination is based- on the presence of Z and W chromosomes where females have ZW chromosomes, and males have ZZ chromosomes. Sex Determination in Honey Bee: o Honey bees have haplodiploid sex determination, where females have 32 chromosomes (diploid) and males have 16 chromosomes (haploid). o Males develop from unfertilised eggs.

Sex-Linked Inheritance:

o

Sex-linked inheritance refers to the inheritance genes of located on the sex chromosomes, X and Y.

Oswaal CUET (UG)

50

X chromosome.

Scan to know

one Y chromosome (XY), while females have two X chromosomes (XX). Geneslocated on the X chromosome are called X-linked genes and play a significant role in sex-linked inheritance.

o

more about this topic

o

X-Linked Dominant Inheritance:

o

Sex linked

inheritance

o

o

o

Hemophilia: Hemophilia is an X-linked recessive disorder. It affects the blood's ability to clot properly. allele from Males who inherit one X-linked hemophilia develop the more are likely their carrier mother chromosome a disorder because they lack secondX a allele. healthy with passed the Example: Queen Victoria of England leading descendants, hemophilia allele to several ofher as Disease." "Royal the association to its historical

2.

Colour Blindness: X-linked

blindness is another colour ecessive trait. o Affected individuals have difficulty of distinguishing between red and green colours. on the X o Since the gene for colour vision is located have common who males, in more is it chromosome,

o Red-green

only one X chromosome. o Example: A son may inherit the colour blindness allele not exhibit a from his mother, who is carrier but does the trait herself. 3. Duchenne's Muscular Dystrophy (DMD):

o Duchenne's muscular dystrophy

is

an

disorders are dominant, meaning Some X-linked that is sufficient to cause the ocondition. one imutated allele Affected individuals can inherit the condition from a

sex. affected parent of either domin o Example: Rett syndrome is an X-linked a disorder, and females who inherit mutated allele nh exhibit the condition.

Examples of X-linked Inheritance: o

affects males,while v Example: DMD primarily females mutated allele passing the carriers, are usually totheét

Sons.

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1.

Bank BIOLOGY

disorder because they lack

Plant Breeding o Plant Breeding is the purposeful manipulation plant of species in order to create desired plant species in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant. o Classical plant brecding involves crossing or hybridisation of pure lines, followed by artificial selection to produce plants with desirable traits of higher yield, nutrition and resistance to disease. o In India, agriculture accounts for approximately 33 percent of India's GDP and employs 62 percent of the population.

>

The main steps in plant breeding are o Collection of variability is the collection and preservation of all the different wild varieties, species and relatives of the cultivated species. The entire collection having allthe diverse alleles for all genes in a given crop is called germplasm collection. o Evaluation and selection of parents isthe identification of plants with desirable combination of characters. The selected plants are multiplied and used in the process of hybridisation. o Cross hybridisation among the selected parents to obtained desired crop characters for example high protein quality of one parent may need to be combined with disease resistance from another parent. This 1S possible by cross hybridising the two parents to produce hybrids that genetically combine the desired characters in one plant O Selection and testing of superior recombinants -The selection process is crucial to the success of the breeding objective and requires careful scientific evaluation of the progeny. This step yields plants that are superior to both of the parents O Testing, releasing and commercialisation of new cultivars -The newly selected lines are evaluated for their yicld and other agronomic traits of quality, disease resistance, etc.

Some Indian Hybrid Crops o Wheat and Rice: •

Hours

iMax. Qucstions: 50

Production ofwheat and rice increased tremendously between 1960-2000 due to introduction of semi dwarf varieties of rice and wheat. This phase is often referred to as the Green Revolution.

•

In l963, several varicties such as Sonalika and Kalyan Sona, which were high yiclding and discase resistant were introduced all over the wheat growing field of India. Semi-dwarf rice varieties were derived from IR-8, and Taichung Native-1 were introduced in 1966. Later better-yiclding semi-dwarf varieties Juya and Ratna were developed in India. o Sugar cane: • Saccharum barberi and Saccharum officinarum were crossed to get the desirable qualitics of high yield, thick stems, high sugar and ability to grow in the sugar cane arcas of north India. O Millets: Hybrid maize, jowar and bajra are developed in India. These varicties are high yiclding and resistant to water stress.

Plant Breeding for Disease Resistance o Several fungal, bacterial and viral pathogens affect the yield and quality of plant products. To minimise this loss disease resistant varieties were developed. Breeding is carried out by conventional method or by mutation breeding. Steps for brecding discase resistant plants: Selection of genome with disease resistant traits

o

o

Mating of the selected parents Selection of superior hybrids Testing of the hybrid for superior variety • Release of the new variety Some crop varieties bred by hybridisation and selection for discase resistance to fungi, bacterial and viral disease are released

Crop Wheat

Variety

Himgiri

Resistance to diseases

Leaf and stripe rust, hill bunt

Brassica Cauliflower

Pusa swarnim (Karan rai) Pusa Shubhra Pusu Snowball K-!

Cowpea Chilli

Pusa Komal

Pusa Sadabahar

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101

PRODUCTION

Mutation is the proccss by which genetic variations are reated through changes in the base sequence within aenes resulting in the creation of a ncw character or Bit not found in the parental types. It is done by using mutants like chemicals or radiations. This proccss is called mutation breeding. Example: Mung bean resistance to ycllow mosaic virus and nowdery mildew were induced by mutation. Resistance to yellow mosaic virus in bhindi (Abelmoschus esculentus) was transferred from a wild species and resulted a new variety of A. esculentus called Parbhani kranti.

Nucleus Plasmalemma Cellwall / Vacuole Ccllulase

Plant cell

Pectinase Protoplast A

Parent B protoplast

Parent A

wprotoplast

PEG

ICell fusion

Plant breeding for Developing Resistance to Insect Pests o Crop plant and crop products are destructed by insects and pests on large scale. To prevent this loss new varieties resistance to them are developed. o Steps for breeding discase resistant plants:

.

Selection of genome with disease resistant traits Mating of the selected parents Selection of superior hybrids . Testing of the hybrid for superior variety Release of the new variety o Some released crop varieties bred by hybridisation and selection for insect pest resistance are Crop Brassica (rapeseed

Insect Pests

Varlety

Pusa Gaurav

Aphids

Pusa Sem 2, Pusa Sem 3,

Jassids, aphids andfruit

Pusa Sawant

Shoot and Fruit borer

mustard)

Flat bean |Okra

(Bhindi)

borer

Pusa A-4 >

Tissue Culture: o The capacity to generate whole plants form any cellexplant is called totipotency. o Thousands of plants can be produced from expalnts in short interval of time using medium, nutrient suitable use of aseptic condition and phytohormones. This method of producing thousands of O

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INuclear fusion

tt

bcs

Somatic hybrid cell B

different varieties is called somatic hybridisation and these hybrids are called somatic hybrids c

Single Cell Protien (SCP) o Single-cell protein refers to the crude,

a refined or pure cultures, microbial edible protein cxtracted from biomass. or cell dried dead, o They can be used as a protein supplement for both la humans or animals. o Microorganisms like algae, fungi, yeast, and bacteria have very high protein content in their biomass. These microbes can be grown using inexpensive substrates like agricultural waste viz. wood shavings, sawdust, corn cobs etc. and even human and animal waste. o Microbes like Spirullina can be grown easily on materials like waste water from potato processing manure and plants having starch, molasses, animal can serve and quantities even sewage to produce large as food rich in protein minerals, fats, carbohydrates and vitamins.

Biofortification: o

Plant Tissue

Culture

plant

is

o called

micropropagation. genetically identical to Each of these plants wil1 be grown, i.e., which they were the original plant from plants like food important Many hey are somaclones. tomato, banana, apple.

o

In 2000, maize hybrids with twice the amount of the amino acids, Iysine and tryptophan than the existing hybrids were developed for improving cultivated Wheat variety, Atlas 66, having a high protein content, has been used as a donor for improving

Meristem Culture:

plants of healthy plants from diseased OThe recovery the plant is .Although culture can be done by mersitem (apical and axillary) Infected with a virus, the meristem remove the meristem can one S tree of virus, Hence, vius-free plants. and grow it in vitro to obtain

Somatic Hybridisation: their plants and after O Isolation of single cells from cytoplasms of two the fusing digesting their cell wall

Biofortification is the process of breeding crops with higher levels of vitamins and minerals, or higher protein and healthier fats. Breeding for improved nutritional qualities have following objectives of improving Protein content and quality. Oil content and quality Vitamin content •Micronutrient and mineral content Examples of Biofortified crops:

cultivated wheat.

o

The Indian Agriculture Research Institute (IARI), New Delhi have released many varieties of vegetables crops rich in vitamins and minerals like

Chapterwise Question Bank BIOLOGY Oswaal CUET (UG)

102 o

vitamin A cnriched carrot, spinach and pumpkin

o vitamin C enriched bitter guard, bathua, mustard

o o

iron and calcium enriched spinach and bathua; protein enriched beans broad, lablab, French and garden peas.

of caring for and breeding domestic animals and the development of genetic traits such as high yielding. disease resistance, ctc. that are valuable to humanity.

Animal husbandry involves breeding and raising livestock sheep etc. like buffaloes, cows, goats, camels, horses, fisheries. and is even extended to poultry farming and Some of the salient practices of animal husbandry

are as follows:

Management of Farm and Farm Animals o Dairy Farm Management

•

• •

-

milk Dairying is the management of animals for its In farm dairy consumption. human for and its product management, we deal with processes and systems that increase yield and improve quality of milk. Selection of good breeds having high yielding is potential, combined with resistance to diseases very important. a The feeding of cattle should be carried out in

while

milking, storage and transport of the milk and products. Management- Poultry includes o Poultry Farm domesticated birds used for food or for their eggs. It with turkey mainly includes chicken and ducks and components of poultry farm geese. Important and management includes

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o

>

•

-

Animal husbandry o Animal husbandry is the science

scientific manner (quality and quantity of fodder). well, should 1 have propet Cattle have to be housed free water and be maintaincd discase areimportance Strict cleanliness and hygiene

I

2

.

Sclection of disease free and suitable breeds condition. • Proper and safe farm care. Hygiene and health Proper feed and water. animat. Animal Breeding - It aims at increasing yields of and improving the desirable qualities of the productA simil breed is a group of animals related by descent and most of characters like general appearance, features, size, configuration etc. There are two kinds of breeding Inbreeding and Outbreeding o Inbreeding- breeding between animals of same breeds

o Outbreeding- crosses between different breeds. o Inbreeding - It is the breeding between animals within the same breed for 4 to 6 generations. The strategy is as follows

• Superior females (e.g.; a cow that produces more milk per actation) and superior males (eg: a healthy bull) which of the same breed are identified and mated.

Breeding

Outbreeding

Inbrecding

Outcrossing

Cross Breeding

The progeny is evaluated.

•

•

Interspecific Hybridisation

O

Again, the superior female and superior male are identified for further mating. Inbreeding increases homozygosity so it is only done if a pureline of animals are to be evolved.

Inbreeding depression - continued inbreeding reduces fertility and even productivity. This is callcd Inbrecding Depression. Whenever this becomes a problem, selected animals of the breeding population should be mated with unrelated superior animals of the same breed. This usually heips restore fertility and yield.

an o Out-erossing- this is the practice of mating ofancestors common same within the breed but having no generation. on either side of 4-6 their pedigree up to often Out-crossing

The oftspring are called out-cross. helps to overcome inbreeding depression.

o

o Out-breeding-

is the breeding of unrelated animals, which may be between individuals of same breed but, having no common ancestors or between different breeds (cross breeding) dilferent species (interspecific hybridisation).

are mattu Cross breeding- sunerior male of one breed another of females with superior female of another o qualities desirable the breed. Cross breeding allows two breeds to be combined, Example; Hisardale sa Manno breed of'sheep developed in Puniab by crossing rams and Bikaneri ewes

Interspecifie hybridisationof twa different species are combine desirable features

mule. o

male :and

mated. of

animals

female progeny

The parents. Et-

both and carmii

Controlled brecding experiments -They are collected out using artificial is semen i insemination. The

MPROVEMENT IN

FOOD PRODUCTION

103

&

male that is chosen as a parent and injected from the tract of the selected reproductive the female by the into

breeder. The

scmen

can be used immediately

or

frozen and used later,

can

cosmetics and polishes

o The most common species of honey bee is Apis indica. Bee-keeping is not labour-intensive. o The following points are important or successful bee

o be

keeping

The frozen: semen can also be transported as per the requirement. The method helps to overcome several problems of normal matings.

o o o o o

Maltiple Ovulation Embryo Transfer Technology

MOED: This technology is used to increase the ccess rate of artificial insemination. In this method:

.

o

Example- High milk-yielding breeds of females catle and high quality meat- yielding males cattle have been bred by this method to increase heard size in a short time.

ey

s

Bee-keeping:

>

o

cow is administrated hormones (FSH) to induce follicular maturation and super ovulation, instead of one cgg: they produce 6-8 eggs. The fertilised eggs 8-32 cells stages, are recovered non-surgically and transferred to surrogate mothers. . The genctic mother is available for another round of super ovulation.

ApicultureA or o

Knowledge of the nature and habits of bees. Selection of suitable location for keeping the beehíves Catching and hiving of swarms seasons. Management of beehives during different beeswax. Handling and collection of honey and of Keeping beehives in crop fields during flowering period yield. increases pollination efficiency and improves the catching. Fishery is an industry. which includes processing or selling of fish, shellfish and other aquatic animals like prawn, crab, lobster, edible oysfegr, etc... are catla, rohu and () The common freshwater fishes common carp. are eaten include (ii) Some of the marine fishes that Pomfrets. and Hilsa, Sardines,Mackerel to (iii) Fisheries provides income and employment in especialiy farmers, and fishermen millions of coastal states in Indian cconomy. on different (iv) To meet the increasing demand fisheries, are techniques like aquaculture and pisciculture applied.

apiculture is the maintenance of hives Bec-keeping of honeybces for the production of honey.3 o Honey is a food of high nutritive value and also finds use in the indigenous systems of medicine. o It also produces beeswax, used in preparation of

to (v) Blue revolution is the movement launched products. fish and fsh increase the production of It is being implemented in the same lines as green

revolution.

OBJECTIVE TYPEQUESTIONS AJ MULTIPLE CHOICE QUESTION: L.

Match List-I with List II.

[CUET 2023]

List-II

RList-1 ()

(A) Sterilized plant part

Pomato

(B) Genetically similer plants

(II) Virus free culture

(C) Meristem

(I)

Somaclones

(IV)Explant hybrids answer option given below; the from Choose the correct (A), (B)-11), (C)HI), (D)-(1V) |(D) Somatic

(4)

6) (AMI), (B)-U), (C)-(Il), (D)-{IV)

() (AMI), (B-W), (4)

2

(C)-(V), (D){11)ing

(AMIV), (B)-(), (C)-I), (D)) technique. (CUET 2022) Pomato is developed

by

(a) Micropropagation (c)

Biofortification

(b) Mutation breeding Somatic hybridization

(d) contains usSue culture, the nutrient medium usually (CUET 2022| as a carbon source. (a) Sucrose (b) Maltose (() Carbon dioxide (d) Calcium carbonate

4.

Protoplasts are obtained by digestion of.

cells. (a) Nuclei (c) Cell walls

of the [CUET 20221

(b) Plasma membranes (d) Proteins 5. Totipotency can be defincd (a) Capacity to generate whole plant trom any cellexplant. (b) Capacity to survive in unfavourable enviroament condition. (c) Ability to conduct water in 100 meter tall tree.

as

(d) The duration of dormancy of seeds and other propagules in |CUET 2022| angiosperms. 6. Biofortification refers to: (a) Sources of proteins for animal and human nutrition. (b) Production of somatic hybrids. (c) Use of mutation breeding.

(d) Breeding crops with higher levels of vitamins and minerals, or higher protein and healthier fat. 7.

Protoplast is. (a) another name for protoplasm. (b) an animal cell. (c) a plant cell wihout a cell wall. (d) a plant cell.

Oswaal CUET (UG) Chapterwise Question

104 8.

18.

Germplasm storing centre in India

is:nke FRI2

(a) NEERI

(b)

(c) CDRI

(d) 1CRISAT.

9.

(a)

&

e

plant.i

(c) part

of the plant used in tissue culture. the plant that expresses a specific gene. tof (d) part Which of the following step is 19. the main root of any plat breeding programme?

(b) rice. (d) tobacco

(c) millet.

is

(b) part of the plant.

Sonalika and Kalyan Sona are varieties of:

(a) wheat.

Àn explant

dead

Bank

10. Micro-propagation is:

(a) Genetic variability

(a) propagation of microbes in vitro. (b) propagation of plants in vitro. (C) propagation of cells in vitro.

b) Evaluation and selection of parents

(d) growing plants on smaller scale. 11. The term 'totipotency' refers to the capacity of a:

20. Which of the following is not included in germplasn ob collection? (b) Old improved varieties (a) Wild relatives (c) Diseased varieties (d) Pure lines 21. The biggest constraint of plant breeding is: INCERT Exemplar,Q. 15, Pg, 63 (a) availability of desirable gene in the crop and its wild relatiy

(c) Cross hybridisation among the selected parents (d) Selection and testing of superior recombinants

(a) cell to generate whole plant. (b) bud to generate whole plant. (c) seed to germinate. (d) cell to enlarge in size. Directions: In the following

12. Inbreeding is carried out in animal husbandry because it:

(a) increases vigour.

(b) infrastructure.

13. To isolate protoplast, one needs:

(c) trained manpower. (d) transfer of genes from unrelated sources. 22. A collection of all the alleles of all the genes of a crop plart is called: [NCERT Exemplar, Q. 25, Pg. 653 (a) germplasm collection. (b) protoplasm collection.

(a) pectinase.

(c) herbarium.

(b) cellulase.

23. Animal husbandry and plant breeding programmes are the examples of: [NCERT Exemplar, Q.4, Pg. 6] (a) reverse evolution. (b) artificial selection.

(b) improves the breed.

(c) increases heterozygosity.

(d) increases homozygosity.

(c) both pectinase and cellulase.

(d) chitinase.

14. In virus-infected plants the meristematic tissues in both apical and axillary buds are free of virus because: (a) the dividing cells are virus resistant.

(b) meristems have anti-viral compounds. (c) the cell division of meristems are faster than the rate of viral multiplication.

(d) viruses cannot multiply within meristem cell (9). 15. Lysine and tryptophan are:

(b) non-essential amino acids. (c) essential amino

t

acids.h'Nais

(a) 60 per cent of the population. (b) 70 per cent of the population. (c) 30 per cent of the population. (d) 62 per cent of the population.

ots

(b) agriculture. (C) export.

(d) small-scale cottage industries.

24. More than 70%

te

of livestock population is in: [NCERT Exemplar, Q.22,

Pg. 6l]

(b) India. (d) India and China.

(a) Denmark. (c) China.

25. The chances of contacting bird flu from a properly ocka (>100°C) chicken and egg are: 0 [NCERT Exemplar, Q.1,Pg

26.

(b)

high.

(d) none. apicultureists the following products of : in cosmetics and polishes? Q. 21, Pg [NCERT Exemplar, Which

one

of

(a) Honey

(b) Oil

(c) Wax

(d) Royal jelly

28.

(a) (b) (e) (d)

shurd

descent and

group of animals, which are related1by b many similarities, are referred to as: Exemplar, ke [NCERT (a) breed. (b) race. (c) variety. (d) species. A

17. 33 percent of India's (Gross Domestic Product) comes from:

(a) industry.

(d) natural selection.

(c) mutation.

(a) very high. (c) moderate.

(a) proteins.

(d) aromatic and no acids. 16. The agriculture sector of India employs:

(d) somaclonal collection.

Fungicides and antibiotics are chemicals that: enhance yield and disease resistance. respectively. kill pathogenic fungi and bacteria, kill all pathogenic microbes. respectively. kill pathogenic bacteria and fungi,

MPROVEMENTIN

FOOD PRODUCTION

105 certain chemicals and radiation to change the base sequcnces of genes of crop plants as: is

of 29. Use

a (b)

temed INCERT Exemplar, Q.9, Pg. 62] rcombinant DNA technolog. transgenic mechanism.

brecding. (c) mutation therapy. gene (d)

30.

(a)

Micro-propagation is: [NCERT Exemplar, Q. 17, Pg. 63) propagation of microbes in vitro

of plants in vitro. propagation of cells in vitro.

(b) propagation (c) (d)

n

growing plants on smaller scale. Several South Indian states raise 2-3 crops of rice annually. The acronomic feature that makes this possible is because of:

(a) shorter

rice plant

)

better imigation facilities

(c)

early yielding rice variety

a) isease resistant rice variety

BASSERTION & REASON: Directions: In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as: (A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A). B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A). Assertion (A) is true but reason (R) is false. (O (D) Assertion (A) is false but reason (R) is true

2.

Assertion: The queen honey bee copulates only once in her life time. as as Reason: The honey bee queen can lay fertilized well eggs. unfertilized Assertion [Al: Biofortification is a type of new "Green

3.

Revolution". Reason R]: Biofortification aims to increase nutrient common and easily levels in crops which are most available. Assertion: Bjiofortification is used to increase nutrient

d.

value of crops. culture Reason: To obtain virus resistant plants meristem id done productivity of milk,c ross

1.

e

7.

Assertion (A): To increases the breeding of dairy animals is done lactation period Reason (R): Cross breeding increase the

of dairy animals a superior animal of Assetion: A single outcross between superior animal of another lhe inbreeding population and can overcome same breed the unrelated population of n inbreeding depression. the chances Keason: Crossing unrelated animals decreases of homozygosity in progeny. provided with Assertion (A): Broiler chicken should be Protein and fat-rich food grown to proyide cggs of Keason (R): Broiler chicken is good quality.

Assertion: The yield of milk is is primarily dependent on the quality of brceds in the farm Reason: Selection of good breeds having high yíelding potential combined with resistance to disease is very important.

Assertion: Light is essential in poultry farn management. Reason: For optimum production of eggs 14-16 hours of light including day light is required 9. Assertion: The single cell protein (SCP) use can help to reduce environmental pollution. Reason: SCP producing organisms SCP can be easily grown on straw, molasses, waste water from potato processing plants, sewage, etc. 10 Assertion: Single cell proteins can help to meet increasing demands of growing population. Reason: SCP now can be produced in high amount commercially, using low cost substrates.

8.

[C| COMPETENCY/CASE-BASED QUESTIONS: Read the following passage and answer the questions (1-5) given below: Animal breeding is another part of animal husbandry. Breeding of animals aims to develop high-yielding animals and improve the desirable qualities of the produce. Animal breeing includes inbreeding and outbreeding. Inbreeding refers to the practice of mating closely related superior males to superior females within the same breed for 4-6 generations. The superior males and females among the progenies are further mated for developing Mendelian pure lines which are homozygous in nature. However, continued close inbreeding eventually decreases fertility and productivity; a phenomenon known as inbreeding depression. And Out-breeding is the breeding of unrelated animals that can be carried out in three different fashions. When two unrelated individuals of the same breed who do not have a common ancestor for the past 4-6 generations are mated, it is called out-crossing. Mating between a superior male of one breed and a superior female of another breed to give a progeny with the combined qualities of both breeds is known as crossbreeding. When males and females across different related species are mated, it is known as interspecific hybridization. 1. Which of thefollowing is not an aspect of animal breeding? (a) Improve desirable qualities of breeds (b) Increasing the yield (c) Making diseased organisms (d) Making disease resistance breeds I.

2.

(a) (b) (c) (d)

What is a breed? Animals related by descent Animals related by an ascent Animals not related at all Clone of animals

What is inbreeding? (a) Mating of closcly related species (b) Mating of unrelated species (c) Mating of clones (d) Mating of different breeds 3.

The aim of Animal breeding programme is: (a) Develop high-yielding animals (b) Improve the desirable qualities of the produce

4,

(c) Develop disease resistançe animals

(d) Both (a) and (b)

Oswaal CUET (UG)

106

BIOOGT

Which brceding depression?

5.

Chapterwise Question Bank

is used

to

overcome

inbreeding 6

(b) Cross-breeding (a) Out-crossing (c) Interspecific hybridisation (d) Inbreeding II. Read the following passage and answer the following

questions: Tissue Culture is a method under which fragments ofplants and animal Tissues are cultivated and grown in a laboratory. The organs, many times, are used for Tissue Culture. Broth and agar are the media used for the growth of the Culture. This method is also known as micropropagation. a sterile workplace, a greenhouse, trained manpower, and a nursery are all it requires. It is beneficial for the production of disease-free plants and plants in developing countries. In developing countries, oil palm, banana, plantain, eggplant, pincapple, rubber tree, tomato, sweet potato have been produced by Tissue Culture. Tissue culture include

Primary culture and secondary culture are Seed The important types of tissue culture techniques Culture -lt involve in-vitro derived formation of plant into a laboratory where they proliferate. Embryo Culture: Embryo Culture involves the in-vitro development of an embryo. Callus Culture:- Formation of a complete plant from undifferentiated mass of cells called callus. Organ Culture:- In it any organ of the plant such as a shoot, the leaf can be used as an explant. Protoplast Culture and

(a)

Meristem Culture was first developed Tissue culture technique by White (b) Haberlandt

t

(d) Skoog (c) Halperin 7. The meristem culture involves culturing which

partof

te

plant (b) Root

(a) Stem (c)

Meristem

8.

Which of

(d)

Leaves

the following is not an application

culture? (a) Rapid Clonal Propagation (b) Somaclonal Variationsee (c) Embryo rescue

of tiss

od

(d) Transgenic plants 9. Plant cell and cell wall together constitute the

(a) Mitochondria and cytoplasm

(b) Protoplast (c) Cytoplasm and cell wall (d) Plasma membrane without cytoplasm 10. Which

of the following plant's meristem has not bee successfully cultured? (b) Apple (a) Banana (c) Sugarcane (d) Potato

ANSWER KEY [AJ

MULTIPLE CHOICE QUESTIONS

1.(d)

2. (d)

3. (a)

4. (c)

5. (a)

6. (d)

7. (c)

8. (d)

9. (a)

10. (b)

11. (a)

12. (d)

13. (c)

14. (c)

15. (c)

16. (d)

17. (6)

18. (c)

19. (a)

20. (c)

21.(a)

22 (a)

|23. (b)

24. (d)

25. (d)

26. (c)

27. (a)

28. (b)

29. (c)

30. (b)

1. (b)

2. (a)

|3.(c)

9.(a)

10.(a)

1. (c)

2. (b, a)

B] ASSERTION & REASON (c) 5.(a)6. (b)8.(a) TC|COMPETENCY/CASE-BASED QUESTIONS 5. (a)6. 4. (c, d) 3. (a) (b) 7. (c) 8.(c) 7.

4. (a)

9.

(b)

10. (b)

ANSWERS WITH EXPLANATION IAJ

MULTIPLE CHoICE QUESTIONS:

Option (d) ís correct. Explanation: The explant is the tissue or plant part which is introduced in the culture media for the regeneration of the plant. 1.

It is primarily sterilised well to remove all the dirt, bacteria, or infections stuck on the surface of it to ensure that the resulting plant produced will be free from any diseases. Somaclones are the genetically identical plants produced by using the somatic cells or the vegetative parts of the plants through the tissue culture technique Meristem culture involves utilizing apical and axillary meristems as explants. It can help in obtaining virus-free plants as meristems are generally free from virus even if the plant is

affected. Pomato was developed by somatic hybridization (protoplast fusion)

of two different genera tomato and potato. It is intergeneric somatic hybrid.

Option (d) is correct Explanation: Pomato was developed by somatic hybridizznon 2.

(protoplast fusion) of two different genera tomato and poc It is intergeneric somatic hybrid. 3. Option (a) is correct Explanation: In tissue culture, the nutrient medium-usuy culure contains sucrose as carbon Source, Sol. In tissuenutritional sucrose is typically used as a the carbon source in media. 4. Option (c) is correct. treated are first Explanation: The two cells of target plants preparatioa for the with the pectinase and wall cellulase enzymes protoplast fusion. These enzymes break down the cell resulting in the creation of bare protoplasts. 5. Option (a) is correct wthole generate plant Explanation: Totipotency is the capacity to ofap plant from any cel/explants. It is the genetic potential totipotencyis cell to produce the entire plant.

In

other words,

107

PRODUCTIONs

I

MPROVEMENTIN FOOD

characteristic in which the potential for foming all the adult organism is retained. typesin the llOption (d) is correct Eylanation: Biofortification is the process of breeding vitamins, minerals, proteins and with higher levels content. This method is employed ecell

of

to improve

fàt health.

public

Protein(SCP) is one

of the sources of proteins for nutrition. human and ninal hybrids are produced by somatic hybridization. Somatic

Single Cell

Mutation

breeding is one of

resistant, disease

the methods for making

crops

Option (3 c) is correct. Eplanation: A protoplast is a plant, bacterial or fungal cell cell wall is completely or partially removed using either

1

nst

machanical

or enzymatic me

Option (d) is

&

alnation:

correct.

Germplasm storing centre in India is ICRISAT

emational Crops research institute for Semi-Arid tropics (Patancheru). ated at Hyderabad correct. 9. is Option (a) Ernlanation: Sonalika and Kalyan Sona are varieties of

eat. Sonalika is developed from high yielding, semi-dwarf, in fliser-responsive wheat variety. They were developed 1963 at Indian Agriculture Research Institute (IARI), New Delhi, as a part of systematic programme for breeding semi dwarf wheat

varieties.

Option (b) is correct. Erplanation: Micro-propagation is propagation of plants in iro (tissue culture) to achieve a large number of plants in very short durations. This results in genetically identical plants shich are widely used in forestry and floriculture. 10.

Option (a) is correct. Erplanation: The capacity of a cell or an explant (any part of a whole plant taken out and grown in test tube) to grow into plant is called totipotency. 11.

12 Option (d) is correct. Eplanation: Inbreeding increases homozygosity, that is, state of possessing two identical alleles, one inherited from a pure line in cach parent. It is necessary if we want to evolve genes that zIy animal. Inbreeding exposes harmful recessive eliminated by selection. It also helps in accumulation of genes. Superior genes and elimination of less desirable

e

Option (c) is correct Lplanation: Pectin and cellulose are the main components of he cell wall of plant cells. These can be removed by digestion enzymes to Kith a combination of pectinase and cellulase 15olate the protoplast. 14. Option (c) is correct planation: In virus-infected plants, the meristematic tissues the apical and axillary buds are free of virus because plication of meristematic cells is faster than replication uses, The main reason behind it is the gene silencing. nor do the meristems dividing cells are vius resistant 13.

O

LT

bave antiviral I5.

compounds. Option (c) Is correct

normal Essential amino acids are required for dietary with and growth. These are usually supplied protein because these are not synthesised by the body. Lysine Dd tryptophan are of essential amino acids. Explanation:

health

types

Option (d) is correct 1Explanation:

India is

mainly

an agricultural

country. The

the agriculture sector of India employs nearly 62% of Population.

17. Option (b) is correct

Eplanation: Agriculture accounts

for approximately 33% of

India's GDP (gross domestic products). 18. Option (c) is correct. grown in a Explanation: Any part of a plant taken out and a media is nutrient special in test tube under sterile conditions an called explant. 19. Option (a) is correct any breeding Explanation: Genetic variability is the root of programme. In many crops, pre-existing genetic variability crop. Collection and is available from wild relatives of the species and varieties, wild different the all preservation of a relatives of the cultivated species is pre-requisite for effective exploitation of natural 20. Option (c) is correct or seeds having Explanation: The entire collection of plants crop is called as all the diverse alleles for all genes in a given germplasm collection. It consists of all present-day improved varieties, old improved varieties no longer in cultivation, local varieties of all areas, pure lines maintained by plant breeders, wild relatives and related species. 21. Option (a) is correct. Explanation: The biggest constraint of the plant breeding is genes the availability of limited number of disease resistance or crop wild varieties that are present and identified in various relatives. 22. Option (a) is correct. Explanation: The entire collection of plants/seeds which have all the diverse alleles for all genes in a given crop is called germplasm collection. Protoplasm collection refers to collection of protoplast (i.e., plant cell without cell wall). Herbarium is a museum of preserved plants that are used for botanical research, mainly

in identification and classification of plants. Soma-clonal collection consists of those plants that are produced from a single cell which are genetically variable from their parents. 23. Option (b) is

correct

Animal husbandry and plant breeding programmes are the examples of artificial selection, Artificial selection isaprocess in which human choose only those traits or characters which are transferred into their offspring. Mutation is a sudden change in DNA sequence due to mutagenic agents like chemicals and radiations. Natural selection is a slow process by which biological traits become either more or less common in a population as a function of the effect of the changing environment. Reverse evolution or devolution is a concept in which species can change into more primitive formms over time. 24. Option (d) is correct Explanation: It is estimated that more than 70% of the world's livestock population is in India and China.

Explanation:

25. Option (d) is

correct.

Explanation: The chances of contacting bird flu from properly cooked (>100°C) chicken and cgg are negligible. Highly pathogenic strains of avian influenza can be found inside and on the surface of eggs. In an infected bird, it may spread to all the parts including the meat. However, proper cooking at or above 70°C, prior to eating, wil inactivate the virus in the egg as well as in the meat.

(UG) Oswaal CUET

or in other

correct. process 26. Option (c) is keeping) is a (also called bee Apiculture commercial Explanation: for management of honey bees of rearing and production of the following: for the preparation of wax: It is used in industry (i) Bees kinds. various cosmetics and polishes of finds nutritive value and also high a food of (M) Honey: It is medicine. systems of use in the indigenous for extra-ordinary source of food the is It to believed (n) Royal jelly: values and is queen bees. It is rich in nutrition asa considered being anti-oxidant. Oil is not be a potent product of apiculture.

is a process of induced breeding in crop improvement. It is possible to induce mutations artificially crop in plants through the use of chemical, or radiations (i.e., gamma radiations), and then selecting and using those plants that have the desirable character as a source in breeding.

Recombinant DNA technology involves transferring of a desired gene (trans-gene) from an organism and incorporating it to host organism by genetic engineering to produce a recombinant. Gene therapy is performed mainly in hum It involves replacing a defective gene with a normal one. 30. Correct option: (b) Explanation: Micro-propagation is propagation vitro (tissue culture) to achieve a large number of plants in very short durations. This results in genetically of plants in which are widely identical plants used in forestry and floriculture.

BJ.ASSERTION

AND REASON QUESTIONS: 1. Option (b) is correct

Explantation: Queen honey bee only copulates life time with drone (male once honeybee). in both fertilized And honeybee can her and unfertilized eggs explanation lay as well of assertion as but store millions after copulation it is not corTect queen of sperms

and they can

life.

honeybee lay eggs through their

2. Option (a) correct Explantation: Biofortification in crops during plantgrowth aimsto increase duringprocessing nutrient rather GreenRevolution,of the crops. than throughmanual levels can means wherethe It be thought as a new aim isto of improve

s

publichealth,

words,

commonly

correct process by which the nutritional Biofortification is the crops is improved through agronomic food of quality conventional plant breeding. or

(c) is 3. Option

mode Biofortification practices, is used to incease biotechnology. Hence a crops is correct statemer value of the nutrient be formed by meristem culture can because Virus-free plants in the whole spread systemically plant except of the viruses a new plant when they colonize the meristems element. Hence, Meristem culture is used phloem vascular to plants is an incorrect statement obtain virus-resistant because obtain virus-free used to plants culture but meristem

host,a

27. Option (a) is correct. are related a group of animals that Erplanation: Breed is like general characters most in are similar descent and

28. Option (b) is correct Explanation: A wide range of pathogen (e.g., fungi, bacteria and virus) affects the yield of cultivated crop species. Fungicides are generally used to control parasitic fungi that either cause economic damage to crop or omamental plants or endanger the health of domestic animals or hum Whereas antibiotics are medicines that help to stop infections caused by bacteria. Therefore, fungicides and antibiotics are chemicals that kill pathogenic fungi and bacteria, respectively. 29. Option (c) is correct. Erplanation: Mutation breeding (also called variation breeding)

Question Bank BIOLOGY

ensure that t everyone can obtainthe nutrients by producing growth and development, required fortheir crops with higher nutritional content,nos available

108

etc. The other three appearance, features, size, configuration, system classification in options are incorrect. Race is used or populations distinct and large into to categorise humans or geographical groups based on anatomical, cultural, ethnic a genetically and morphologically differences. Variety distinct subset of a species that is geographically isolated from as a other populations within that species. A species is defined nature. in interbreed potentially group of individuals that

Chapterwise

is

vius-resistant

plants.Nbsle

Option (a) is correct Explantation: Cross breeding increases the lactation period of a dairy animal and thus the productivity of milk increases.

4.

Option (a) is correct Eyplantation: Inbreeding involves mating closely related a superior animals of breed, continuously for 4-6 generations, a Continuous inbreeding in small I population between related of same animals the breed increases the occurrence ofident (homozygous) alleles in a genotype. lt also leads to gradal loss of fertility, productivity and reducedIweight in the progeny. This is known as inbreeding depression. This is becam closely related parents have a higher chance of transferrine similar alleles to the offspring. Thus, crossing unrelatcd animals decreases the chances of homozygosity in progeny,. Thus it is concluded that both assertion and reason are true statements and reason is the corTect explanation for assertion. 6. Option (c) is correct 5.

Explantation: Broiler chicken requires protein and fat rich food for their fast growth

ratetos and not for laying

They are mostly raised for meat

eggs.

7.

Option (b) is correct Explantation: Milk yield is primarily dependent on the quality of breeds in the farm, as high milk-yielding breeds of females produce more milk per lactation. Selection of good breeds having high yielding potential combined with resistance to disease is very important because it helps in improving the desirable qualities of the produce as well as gives rise

o

superior progeny.

8. Option (a) is correct Explantation:

A

Light For

is essential for high egg production optimum production 14 to 16 hours of lightincluding daylight is S required, reducing photoperiodcan seriously effect egg production as can be changed due one the egg laying patterns to

in poultry birds.

9

hour of

Option (a) correct. is Explantation:

light9

Single Cell edible Protein or SCP protein extracted refers to the dried from pure microbial or cell biomass. cultures, dead, can or supplementIt be used as an alternative protein SOurce for both humans or Microorganisis such as unicellular animals. USed algae,fungi, as SCP. yeast, bacteria can be Algaesuch

as Spirulina on production are widely used for the is rich in protein content. grown using inexpensive It can be easily shavings substrates sawdust, likeaagricultural wastes, WOod Com cobs, processit waste water industry, straw, from the potato animal molasses, wastes, etc. manure, and Sewage, human SCP as it

ROVEMENT

A

Option (9)

N

FOOD PRODUCTON

s correct (SCP)

iprotein It is rich in

Srgle ceil fecd.

109

is protein-rich biomassthat is used 2s good quality protein and poor in fats.

proteins so, it can help to meet singie-cell growing BPopulation. Anantssof the reasons for this claim some of several

the increasing

these are listed i There are reasons are: of the i- SCPSome can be produced using low-cost substrates like dust, Q straW, molasses. padty,

used for SCP have

a

high rate of multiplication. as SCP is independent of Microbial biomass production Microorganisms

ceasonal as well as

climatic variations.

CCoMPETENCY/CASE : BASED QUESTIONS:

correct

Option (c) is an important aspect of Eplanation: Breeding of animals is at increasing the aims l busbandry. Animal breeding qualities of their desirable eld of animals and improving theresistant. disease oduce and making them 1.

correct 2 Option (b) (a) is by descent and group of animals related Eplanation: A appearance, features, general imilar in most characters like a breed. to to belong are said size. configuration, etc., (a) is correct more closely Erplanation: Inbreeding refers to the mating of same breed for 4-6 generations. reiated individuals within the males and superior as follows-superior The breeding strategyis mated in pairs. females of the same breed are identified and 3. Option

4.

Option (c) (d) is correct

develop hígh Eplantation: Breeding of animals aims to desirable qualities of the selding animals and improve the Animals.

Option (a) is correct especially close Erplanation: Continued inbreeding, even productivity. nbreeding., usually reduces fertility and Whenever this becomes This is called inbreeding depression. 5.

a problem, selected animals of the breeding popalztion sonid be mated with unrelated znimals of the same breet This is called as outcrossing nd it often helps to overcome intreeding depression.

6. Option ( b) is correct Explanation: Tissue culture technique was first practised by Haberlandt and Hanning in 1902. Harrison deveoped this technique. The fist successful attempt wzs made by We in case of Tomato root.Gottlieb Haberlandt was 2n Gaa botanist who first developed tissue culture. He poirted ot for the first time that plants cells are totipotent, *hich led to establishment of plant tissue culture. He is knon the fbe of tissue culture. 7. Option (c) is correct Explanation: When the plants are infected with a vins, tte meristem (apical and axillary) is free of the virs becanse the cell division of meristem is faster than the rzte of virs replication and multiplication. 8. Option (c) is correct Explanation: The applications of tissue culture inciude Rapid clonal propagztion, Somaclonal varíations, Transzeric plzrts, Inductíon and Selection of mutations, resistance to weedicides and tolerance to stress like pollutants, toxins, salts, drougt, floods etc. Embryo rescue is the proceure that involves excising weak, on immature plant embryos and culture them in-vitro speially devised culture medium. 9. Option (b) is correct Explanation: Protoplast is a plant cell without 2 cell w2ll Scientists have been able to isolate single cells from plants znd to isolate naked after digesting their cell walls have been able membranes) plastna by protoplasts (surrounded

s

10. Option (b) is correct

of Explanation: Culturing of meristems is important Heoce, cne diseased plnts. from recovery plants healthy of the can remove the meristem and grow it in vitro to obain virs culturing meristens of free plats. Scientists have succeeded in banana, sugarcane and potato.

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CHAPTER

5

10

MICROBES IN

HUMANWELFARE

Revision Notes: >

O

Microbial Diversity

microscopic Microbes are diverse-Drotozoa., bacteria, fungi and are proteinacious that prions also and viroid viruses, plants on earth ranging infectious agents. They are found everywhere Bacteria some places. inhabitable water and from soil, air on nutritive media to form colonies, can grOwn be fungi and very useful in study of which can be seen by necked eyes and

o

distillation of the fermented broth. Antibiotics- They are chemical substances produced can kill or retard the growth by some microbes and was first of other microbes. Penicillin antibiotic to be discovered. Antibiotics have great improved capacity to treat deadly diseases such as plague, whooping cough, diphtheria and leprosy.

Chemical, Organic acids, Enzymes and other Binant: Molecules are commercially produced by microbes

microorganisms. Microbes cause many diseases in human beings, plants and man in diverse animals. Several microorganisms are useful to

Chemicals

•

Aspergillus niger (fungus)-Citric acid

Acetobacter aceti (bacterium)-Acetic acid Clostridium butylicum (bacterium) - Butyric

ways. > Microbes in household products household food

acid Lactobacillus (bacterium)

processing o Microorganisms

-

• Enzymes: Lipase-used in laundry detergents for removing oily stains

-

Pectinase and protease used in for clarifying suspended material from fruit juices.

Streptokinase (Streptococcus bacterium) - used as clot buster (to remove clots)

Microbes in

Household Products

•

o The dough

used for making foods such as dosa and idli is fermented by bacteria. The puffed-up appearance of dough is due to the production of CO, gas. The dough used for making bread is fermented using baker's yeast (Saccharomyces cervisiae). o Cheese, is one of the oldest food items in which microbes were used. The large holes in "Swiss cheese

} Microbes in industrial production A number

of products like beverages and antibiotics involve

uses of microbes. Production on large scale requires growing microbes in very large vessels called fermenters.

o Fermented Beverages- Saccharomyces cerevisiae used

for bread-making and commonly called brewer's yeast, is used for fermenting malted cereals and fruit juices, to produce beverages like wine, bear, whisky and rum. Wne and bear are produced without distillation whereas whisky, brandy and are

um

produced by

Bioactive molecules: Cyclosporin A (Trichoderma polysporum

fungi)

- used as immunosuppressive agent (for organ transplant patients). Statins (Monascus purpureus yeast) blood cholesterol lowering agents.

>

- used as

Microbes in Sewage Treatment o Municipal waste water (sewage) contains large amount of organic matter and microbes which are pathogenie and cannot be discharged into natural water bodies like

2re due to production of a large amount of CO, by a bacterium named Propionibacterium sharmanii. The

'Roquefort cheese' is ripened by growing a specific fungus on them for a particular flavour.

-

Lactic acid Saccharomyces cerevisiae (yeast) Ethanol

like Lactobacillus and other commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. Scan to know The LAB produces acids that more about coagulate and partially digest this topic the milk proteins. It also improves its nutritional quality by increasing vitamin B12. In

our stomach too, the LAB play very beneficial role in checking disease-causing microbes.

:

rivers and streams. o

makeit

Sewage is treated in sewage treatment plant to less polluting by using heterotrophic microbes naturaly

present in sewage. O Sewage treatment is done in two stages

In Primary treatment,

floating

debris is

removed

peo0 by sequential filtration. Grit (soil and small

are removed by sedimentation.

treatment

Secondary treatment or biological large involves passing of primary effiuents in microbes ofaerobic fungal aeration tank to help the growth with into flocs (masses of bacteria associatedd

NvnBMNVWOH

N

S

of

(Stretcccns

drug

2gents Prtezs

mateias

is

action

removzl

palyspr

juce)

involved

used Methcicteri

immunosuppressive

Sadge

brster

purpars

the

sobd

loweing

miarobes

Gas-balder

botted Ivolves

Trichodena

Invoive

ard

Bacteria

coarse

Streptokinase

plant

dot •Pectinases

darity

cholesterol

as used

•Lipas

biogas

of

Monascus

treatment

A-

(o

typical

treatment

•Cydosporin

• blood

•Statins-

an as

A

Water Sewage

used

Dung

e Sewage

2s Secondary

Enzymes

Primary

molecules

in of

Production

Biogas

Micobes

Microbes

Bioactive

SewageIreatment

aád Butyric

in

acid acid

acid

Acetic

bacterum):

welfare

Lactic

Citric

Industrial bacterium):

Products

Microbes

fungus);:

bacterium):

Microbbes

(a

butylicum

in

(a (a niger

aceti

Human

acids

(a

Banic

Lactobacillus

Clostridium Aspergillus•Acetobacter

•

as Antibiotics

biocontrol

Mirobes

agents

beverages

Level

in

bio-fertilizers

as

household

Mirobes

Microbes

Third

notatum

produed

Fermented

caterpillars

Map

Nucleopolyhedrovirus):

Level

Bacteria

Penicillium

Mind

is

Chees

Penicillin

Second

butterfly produced

Fungi

by

Curd

Bread

the

Swiss arthropods

Trace

Cyanobacteria Oscillatoria

bacteria)

Control

Azolla

Level

Azotobacter

is

genus

cerevisiae

shermanii

etc., algae

thuringiensis:

plants

bacteria).

(esp.

Nostoc,

and

insects

green

with

Azospirillum

•Symbigosis:

Propionibacterium

or

living:

Mycorrhiza-

•Rhizobium

sp.

Bacuioviruses

Trichoderma

Saccharomyces

Lactobacilus

living

blue

Controis

•Bacillus

Glomus

Wine,

by

•Free and

(free •

and

LAB

Sacharomys

Beer,

cerevisiue

Anabaena

(symbiotic

brandy

First

in

association

of

•

•

Oswaal CUET (UG) Chapterwise Question Bank BIOLOGT

112

o

o

filaments to form mesh like structures). These microbes increase the consumption of organie wastes and decrease the BOD (biological oxygen demand)of the eftluents. BOD is the amount of oxygen that would be consumed were if all the onganie matter in one litre of water measures amount It organic of the by bacteria. oxidised matter present in the water. Greater the BOD of water

o

is

Microbes as Biocontrol agent o Biocontrol means use of

more it is polluted. Once the BOD of sewage or waste water is reduced, the etfiuent is then passed into a setling tank where the bacterial flocs' are allowed to sediment. This sediment

biochemical for method controlling plant disease and as pests. The chemical used are insecticides pesticides and harmful to human beings and

is called activated sudge. o Sludge is passed into large tanks called anaerobic

sludge digesters in which anaerobic bacteria digest the bacteria and fungi in the sludge and produce mixture of gas called biogas, which is a mixture of methane, hydrogen sulphide and carbon dioxide.

o The efiuents

from the secondary treatment plant are water bodies. released into

pests

Microbes as biocontrol agent

and disease is a method of controlling pest on natural prediction rather than

chemicals.

o The organic farmer creates a system where the

pests

are

not eradicated but kept at manageable level by complex system of check and balance within the living nd vibrant ecosystem. For example • The Ladybird and Dragonflies are used to get nid of

generation

o

Gas

Scan to know more about this topic

animals.

o Biological control of

> Microbes in Production of Biogas Energy Biogas is a mixture of gases produced by the microbial activity that can be used as fuel. o Certain bacteria that grows anaerobically on cellulosic material produce large amount of methane along with CO, and H,. These bacteria are collectively called methanogens (Methanobacterium).

is removed and supplied through an outlet consumption. The spent slurry is removed through another outlet and used as fertilisers. Biogas plant is more oflen build of cattle dug rural areas as large amount available casily.

aphids and mosquitoes respectively.

• On brassicas and fruit tree, to control

butterfly

caterpillars bacteria Bacillus thuringiensis is used. o Biological control developed for use in the treatment of plant disease. For example

•

Gas-holder

Dung Water

CH+CO,tH

Sludge

o

The fungus are free-living fungi that are very common in the root systems that control several plant pathogens. Baculoviruses are pathogens that attack insects ana other arthropods. The majority of baculoviruses used as biological control agents For example

• The

genus Nucleopolyhedrovirus are mgjar baculoviruses. These viruses are excellent candidates for species-specific, narrow spectrum insecticidal applications.

Microbes as Biofertilisers Digester

Fig. 1: Biogas Plant Biogas Plant

o The technology of biogas production was developed in India mainly due to the efforts of Indian Agricultural Rescarch Institute (IARI) and Khadi and Village Industrics Commission (KVIC).

o The excreta of cattle (gobar)

is rich in methanogens bacteria and is used for generation of biogas also called 2s gobar gas. o Biogas plant consísts of a concrete tank in which bio wastes are collected and slurry dung is fed. of OA floting cover is placed over digester that moves upward when gas is produced. The gas produced

fertilisers are organisms that enrich the nutrient quality of the soil, The main sources includes bacten fungi and cyanobacteria. • The root nodule formed by Rhizobium bacteria ot root of leguminous plants increase the nitroge metabolic level soil, necessary for various processes.

O Bio

of

Iiving

and Azospirillum are free bacteria that live in soil and fx atmospheric nitro into organic forms. Azotobacter

angiospemt

Symbiotic association of fungi with fertiligy plants (mycorrhiza) also increase the absorbs of soil. Glomus form mycorrhiza that plant.

the

phosphorus from the soil and passes ittoresistance These microbes also provide benefits like to root-borne pathogens, tolerance to salinity drought.

IN HUMAN

WELFARE

113

MHOBES

(Nostoc, Anabuena, etc), microbes found aquatic and estrial environment lix atmospheric nitroyen, In

Cyanobacterís

paddy field thís acts as important biofertiliser. Blue een alyae also add oryanic matter to the soil and increase its fertility.

gutotrophiC

OBJECTIVETYPE QUESTIONS ATMULTIPLE CHOICE QUESTIONS:

.

pli

Temperature and (b) (c)

2.

) (c) 3.

acidic pli of gut

Exposure to light

(0)

Exposure to light and acidic pli of gut

thurlnglensls is

a

biocontrol ayent ayainst (CUET 2022) (b) Fungal pathogen Nematode pests (d) Bacterial pathogen Inscct The bacteriumn responsible for breakdown of cellulose in a biogas plant is: (CUET 2022) Baclue

Acetobacter acetl (c) Clostrldum

(a)

Which of

(b) Lactobacllus (d) Methanobucterium

the following mícrobe is used

antibiotics?

in production of

(CUET 2022)

(a)

Penlclllum notatum

(b)

Sireptomyces grlseus

(c)

Aspergllus nlger

(d)

Clostrldium butylicium

(e)

Saccharomyces cerevislue

only

B

and

(B) C and D only (D) Cand E only

(C) B and E

(a)

only Statement 1: Baculoviruscs belonging to genus Nucleopolyhedrovirus are used as biological control agent. Statement 2: Thcse viruscs arc used as thcy are species-specific and have narrow spectrum insecticidal applications, so can be a good insecticide. (CUET 2022) In the light of above statements, choose the most appropriate answer from the options given below Both statement and statement 2 arc corrcct.

(D)

Bolh

(C)

Statement

5.

1

statementland statement 2 are incorrcct.

is incorrect and statement 2 is correct. Mr. X had purchased a fruit juice bottle from the market to and is puzzled to see that is completely clear. It is duce

(0) Statement O

(a) Lipase (0)

is correct and statement 2 is incorrect.

1

1

and Pectinase

(CUET 2022)

Amylase and Polymerase

) Pectinase and Proteasediyacie (d) Protease and

1, Bioactive

Ligase

molecules like statins are produced

(a) Trichoderma polysporum

(b)

Monascus

purpureust

(e) Acetobacter

aceti (4) Streptococeus

by:

s

(CUET 2022)

of the

(b) Blood cholesterol-increasing statins: Monacus purpureus (c) Antibíotics : Acetobacter ucetl (d) Red dye: Methanobucterium 9. Big holes in Swiss cheese are made by: (a) a machine (b) a bacterium that produces methane gas (c) a bacterium producing a large amount of carbon dioxide (4) a fungus that relcasesa lot of gases during its metabolic activities Methanogeníc bacteria are not found in: (a) rumen of cattle (b) gobar gas plant 10.

(c) bottom

of water-logged paddy fields

(d) activated sludge 11. The approach to biological control includes

(a) Import and relcase of an ínsect pest provide hosts for natural enemies.

Choose the correct answer from the options given below: (A) A

Which one of the following is the correct match product and the producer? (1) Cyclosporin A: Trichodermapalysporum 8.

protoxin gets converted 1nto an The Inactlve active the...... to (CUET 2022) (orm due of insect'sgut Alkaline

:

a new area to

(b) Import and release of n ural enemies from the native home of an alien insect pest that has invaded a new area. (c) Preservation of natural enemies (predators & parasites) that are already established in an area. (d) Use of insecticides to reduce alien insect pests to establish new cquilibrium position. 12. Dragonflics indicate positive ecological impact as : (a) The presence of dragonflies indicates polluted water.

(h) Dragonfly nymphs selectively cat mosquito larvae. () They help to decrease the probability of diseases spread by vectors. (d) Dragonfly do not cause any harm to beneficial species. 13. The most efTective stages in the life cycle of dragonfly that eradicates mosquitoes are :

(a) Larvac and adult (b) Caterpillar and adult (c) Nymph and adult (d) Pupa and adult 14, What would happen if oxygen availability to activated sludge flocs is reduced? (a) It will slow down the rate of degradation of organic matter. (b) The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs. (c) Flocs would increase in size as anaerobic bacteria would grow around flocs. (d) Protozoa would grow in large numbers. 15. The frec-living fungus Trichoderma can be used for:

(a) killing insects

(b) biological control of plant diseases (c) controlling butterfly caterpíllars

(d) producing antibiotics

Oswaal CUET (UG) Chapterwise Question Bank BIOLOC

114 i6. Wastcwater treatnnent jcherates a lange quantity of sludge, which can be treated by:

Choose the correct

(a)

(b)

() digesteis

(c)

(2) activäted sludge

(3) chemichts (4) 0xidation pond 17. BOD of waste water is estimated by mcasuring the amount of:

(d)

match.t

-(ii), B - (ii), C-(iv), D -(i)b A-(ii), B - (iv), C - (iii), D -(i) A -(iv), B - (iii), C- (ii), D -(i) A-(iv), B-(i), C- (ii), D- (ii) A

primary trcatnent removal of: (a) dissolved impurities. 26.

of

The

waste

water

involves

(b) stable particles, (d) harmful bacteria.

(a) total onganic matter.

(c) toxic substances.

(b) biodegradable onganic matter. (C) oxygen evolution. (d) oxygen consumption.

BOD of waste water is estimated by measuring amount of: (a) total organic matter. bdiet (b) biodegradable organic matter. (c) oxygen evolution. (d) oxygen consumption. 27.

18. The free-living fungus Trichoderma can be used for:

(a) killing insects. (b) biological control of plant discases. (c) controlling butterfy caterpillars. (d) producing antibiotics. 19. The large holes in Swiss cheese are due to (CUET 2023) (a) Production of large amount of O2

28, Match the following list

|NCERT Exemplar, Q. 2, Pg. 69] (b) activated sludge.

(c) chemicals. (d) oxidation pond. 25. Match the following list of bacteria and their commercially important products.

ColumnB (Product)

c)

Lactic acid II.

Clostridium butylicum

d) Lactobaillus

Butyric acid

III, Acetic acid IV, Citric acid

(NCERT Exemplar,

a)

Statin

b)

Cyclosporine A

c) d)

Role Removal of oil stains II. Removal of clots from blood vessels I.

Streptokinase

IH. Lowering of blood cholesterol

Lipase

IV. Immuno-sup-pressive

agent Choose the correct match.

(a) Insecticide (b) Weedicides (c) Rodenticide (d) All of the above 22. Which of the following is not used as a biopesticide? (a) Xanthomonas campestris (b) Bacillus thuringiensis (c) Trichoderma harzianum (d) Nucleopolyhedrovirus 23. The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is: INCERT Exemplar, Q. 1, Pg. 69] (a) vitamin C. (b) vitamin D. (c) vitamin B12. (d) vitamin E. 24 Wastewater treatment generates a large quantity of sludge, which can be treated by:

a) Aspergillus niger b) Acetobacter aceti

bioactive substances and the

Bioactive substance

21. Bacillus thuringiensis is widely used as:

Column A (Bacterium)

of

t

roles.

(b) Citric acid (c) Production of large amount of CO, (d) Ethyl Alcohol 20. Which one of the following microbes forms symbiotic association with plants and help them in their nutrition ? (a) Azotobacter (b) Aspergillus (c) Glomus (d) Trichoderma

(a) digesters.

t

Q. 4, Pg. 69]

(a) (b) (c) (d)

A-(i), B - (ii), C-(1), D – (iv)t A-(iv), B -(ii), C- (), D- (i)h A-(iv), B - (iil), C- (ii), D-(1) A-(ii), B - (iv), C- (ii), D -()

29. Which one of the following alcoholic drinks is produced without distillation? [NCERT Exemplar, Q. 8, Pg. 70j (a) Wine

(b) Whisky

(c) Rum (d) Brandy 30. The technology of biogas production from cow dung was developed in India largely due to the efforts

of

[NCERT Exemplar, Q.9, Pg.

(a) Gas Authority of India. (b) Oiland Natural Gas Commission. (c) Indian Agricultural Research Institute and Khadi Village Industries Commission. (d) Indian Oil Corporation.

BJASSERTION Directions:

&

70

and

REASON:

In the following questions, statement assertion (A) is followed by a statement reason of (R). Mark the correct choice as: (A) Both assertion (A) and reason reason (R) (R) are true and is the correct explanation of assertion (A). reason (R) (B) Both assertion (A) and reason (R) are true but is not the correct explanation assertion (A). of (C) Assertion (A) is true but reason (R) is false. (D) Assertion (A) is false but reason (R) is true.

of

a

MCROBESINHUMAN

ASsertion (A):

milk. Reason (R): improves lhe

An

WELFARE

115

inoculum of curd is used for curdling of

which It contains Lactobacillus, also nutritional quality by increasing vitamin

BI2.

Statin is produced by

Assertion (A): polysporum. Trichoderma

a

yeast called

(R): Monascus piurpureus lowers the blood body. cholesterol level in the Activated i sludge should havethe ability to Asserrtion (A): n

3

setle

quickly. is

to be done to absorb pathogenic water while sinking to the bottom

Reason (R): This kacteria present in Waste

of the 4

and

5.

settling tank,

Cyanobacteria increases Assertion (A): organic matter to the soil.

the soil fertility

also add the

the atmosphere. Reason (R): They can fix free nitrogen genus of Members Glomus form Assertion (A): the mycorrhiza. Reason (R):

Mycorrhiza is an association of plants and

fungi.

Assertion (A): Rhizobium leguminosarum is a symbiotic hacterium found in the root nodules of leguminous plants. Reason (R): They have the ability to fix 1

8.

(c) Exponential growth has two phases lag and log. (d) In logistic growth, population passes well beyond the carrying capacity of ecosystem. 2. Identify the correct equation that represents the exponential population growth curve : (a) dNldt N (b) dNldt = rN (K-NIK) (c) Nt =NOert (d) Both (a) and (c) 3. The equations correctly represents Verhulst-Pearl logistic growth is: (a) dN/dt = rN(K-N)/K (b) dNldt = rNIK (c) dN/dt = N(K-N)/K (d) dN/d= r(K-N)/K 4. The population growth is generally described by the following equation: dN/dt = rN(K- N)/K What does r' represent in the given cquation? (a) Population density at time Y (b) Intrinsic rate of natural increase (c) Carrying capacity

(d) The base of natural logarithm 5. Study the population growth curves (A and B) in the given graph and select the incorrect statement

atmospheric

nitrogen. Assertion (A): Mucleopolyhedrovirus are useful, as they are good biocontrol agents.

density

Reason (R): They are species-specific, narrow spectrum bioinsecticides.

Population

Assertion (A) biofertilisers.

:

K

N

B

Blue green algae are popular as

Reason (R) : Blue green algae cause algal bloom in polluted water bodies. 9.

Assertion: Toddy becomes unpalatable after 24 hours. Reason: The fermentation of toddy is continued by

naturally occurring yeasts. 10.

A/

Assertion : Curd is more nutritious than milk. Reason : LAB present in curd checks the growth of disease- causing microbes.

(C|COMPETENCY/CASE-BASED QUESTIONS: L Read the passage carefully and answer the question given after the passage fromn 1-5. Growth of a population with time shows specific and predictable patterns. Two types of growth pattern of population are exponential and logistic growth. When resources in the habitat are unlimited each species has the ability to realise fully its innate potential to grow in Primary effluent is passed into large aeration tank.

Time (t)

(a) Curve 'A' shows exponential growth, represented by

equation dN/dt=rN. (b) Curve 'B' shows logistic growth, represented by equation dN/dt = r(K-N)/K. (c) Exponential growth curve is considered as more realistic than the logistic growth curve. (d) Curve 'A' can also be represented by equation Nt = NOert. II. Study the following diagram and answer the question given below 6-10 Large quantities of sewage is generated every day in cities and towns, which is treated in Sewage Treatment Plants (STPs) to make it less polluted. Given below is the flow diagram of one of the stages of STP.

Observe the given flow diagram and answer the questions accordingly.

Primary effluent is passed into large aeration tanks: (a) To allow bacterial flocs to settle down 6.

Efiluent passed into settling tank to form

the sediment. umber. Then the population grows in exponential fashion. When the resources are limited, growth curve shows an nal slow rate and then it accelerates and finally slows gving the growth curve which is sigmoid. ldentifythe incorect statement: Exponential growth occurss as b) Logistic growth more in organisms such lemmings. is realistic.

.

(b) To allow fast growth of useful aerobic microbes into flocs (c) To allow anaerobic sludge digestion (d) None of these 7.

Technical term used for sediment formed in sewage treatment is:

(a) Flocs

(b) Eiiuents

Oswaal CUET (UG) Chapterwise Question Banik

116

et

(c) Activated sudge t (d) Anaerobic sludge 8. The significance of the above sediment formed is that: (a) It acts as inoculum (b) It serves in formation

carbon dioxide (b) methane, sulphur and , mono-oxide, methane, hydrogen sulphide (c) carbon nitrogen (d) methane, hydrogen sulphide and

treatment of sewage involves: of large and :small particlesfroom (a) Physical removal sewnqe through filtration digestion (b) Anaerobic sludge remove smaller r and larger Sedimentation to 10. Secondary

of flocs

(c) It helps in formation of natural water bodies (d) It helps in anerobic sludge digestion 9. Identify the correct set of gases produced during digestion of sludge: (a) methane, hydrogen sulphide and carbondioxide

(c)

particles

Mechanical agitation coupled

(d)

with

addition

microbes

of aerobe

ANSWER KEY (A]

1. (a)

2. (c)

3.()

11. (6)

12. (c)

13. (c)

14. (b)

21.(a)

22 (a)

|23. (c)

24. (a)

4. (a)

MULTIPLE CHOICE QUESTIONS 5.(a)

6. (c)

7.(b)

8. (a)

9.(c)

10.(0)

15. (b)

16. (a)

17. (d)

18. (b)

19. (c)

20.(C)

25. (c)

26. (b)

27. (d)

28. (d)

29. (a)

30.(c)

9. (a)

10.(a)

9. (a)

1.()

(B]ASSERTION & REASON 1. (a)

| 2. (d)

3. (C)

1.()

2. (d)

3.(a)

8. (d) 7.(a) 6. (a) 5.(4) QUESTIONS COMPETENCYICASE-BASED (C| 4. (a)

4. (b)

5.(c)

6. (c)

|7. (C)

|8. (a)

ANSWERS WITH EXPLANATION MUITIPLE CHOICE QUESTIONS: Option (a) is correct.

AJ 1.

Explanation: The Bt toxin is produced by the bacterium Bacillus thuringiensis through the process of sporulation. The Bt toxin protein exist as inactive protoxins but once an insect ingests the inactive toxin, it is converted into an active form of toxin due to alkaline pH of the gut which solubilize the crystals. 2. Option (c) is correct Explanatton: Bacillus thuringiensis

is a bio control agent

against insect pests.

3. Option (d) is correct Explanation: The bacteria that are collectively called methanogens and one such bacterium responsible for

breakdown cellulose a biogas plant is Methanobacterium. These bacteria grow anaerobically on cellulosic material produce large amount of methane along with CO, and H, after breakdown. 4.. Option (a) is correct

Explanation: Alexander Fleming dscovered penicillin, the first natural antibiotic in 1928. Penicillium notatum (fungus) produces penicillin, he first antibiotic. Streptomyces griseus a species of bacteria, they are well known producers of antibiotic, streptomycin. It is the first antibiotic ever reported

from a bacterium.

Option (2) is correct Explanation: Baculoviruses are biological insecticides used to control pests insects in agriculture and horticulture. The majority of baculoviruses which are used as biological control agents belong to the genus Nucleopolyhedrovirus, They are species-specific, narrow spectrum insecticidal applications. 5.

They do not show negative effects on mammals, birds, plants fish or even non-target insects. 6. Option (c) is correct Explanation: Clarification, is the removal process important step in the production of suspended material, is fruit juice due to its significant effect on the appearance, flavour and commercialization of juice. The enzymes, pectinases and proteases are helpful in clarifying fruit juices. Pectinase, breaks down the pectin polymer structure and reduces the undesirable of

turbidity. 7.

Option (b) is correct Explanation: Statins are produced by Monascus purpurcs yeast. They are used as blood-cholesterol lowering agents These bioactive molecules. It inhibits the enzymes responsible for synthesis of cholesterol. Trichoderma

polysporum produces an fungus a immunosuppressive agent cyclosporin A, which is used as an immunosuppressive agent in for organ transplant patients. Acetobacter aceti a bacterium produces acetic acid. Streptococcus produces the clot buster enzyme streptokinase. is used to remove clots from the blood vessels of patients Wno have myocardial infarction. 8. Option (a) is correct.

Explanation: Cyclosporine A is produced by Trichodermd immuno-suppressive polysporum(fungus) and is used as an agent in organ transplant patients. used Statins are produced by Monascus purpureus (yeast), Itis as

blood-cholesterol lowering agents. It inhibits the responsible for synthesis of cholesterol.

Acetobacter aceti is a bacterium that produces acetic Methanobacterium is a common methanogen.

enzymes

a

WHUMAN CSESN

117

WEELFARE

czLzsing

i Bg boies a rze of

ti

artat

'Swiss cheese'

21O1

of

CO,

2re

made

by

due

bacterium

sharmai..treiezses czrbon diozide wten lactic acid znd forms bubbles. These bubbles d is responsible for the production of pockets, te

-ce

the ccheese.

rls

CoTect bacteria zre znaerobic microor

Egcntio: Mehenogeic in the presence of carbon diozide 2nd pro

These bacteriz 2re not found in activzted ge Thezrobes presetin the ativzted studge 2re aero3.

siadge

thzt gro# rzpidly and corTect.

ai

form Aocs.

LOpti (b) s to biolozical control includes Eglaion: The pproach of ratrzl enemies(predztorss& parzsites)that are Prsecc 21 The release of natural enemies ay etzblished; in I 2re2 pathogens) to control pests a type

is contro! called augnentztion. This approach uses ticlogicl f are 2pplied in a timely ily zvzil2ble species that evet populztion increascs, or to suppress a pest ica Biological control using parasites is generallypest Whea multiple pests occur (e.g aphids, thrips) natural reeded for ech pest In cases where natural use of a selected ris nevi1lable 1or augmentation, S

e

e

iide tht spares other natual enemies

may be necessary.

20pion (c) is correct. Elnation:Adult dragonífies are beneficial because they eat ying insects, particularly midges and mosquitoes and

itg to decrse

0pion

the probability of diseases spread by vectors.

(c) is correct.

: Dragofies are large and heavy-bodied insects. lavze (or Nymphs), which live in water, eat almost ytng living that is smaller than themselves. The adult dzaciy larvze 2re even knoWn to catch end eat smnall fish. Lsally, they eat bloodworns or other aquatic insect larvze. Drazocfy ymphs are such good hunters because they move aly fzst- by whzt looks Iike jet propulsion. One of the bezets of having dragoafies live nearty isthat, they eat many their weight in mosquitoes every day. Dragonfiies also eat ry differeat kinds of fies. Using a basket-like arrangement of teeir legs, adult dragonflies can actually catch nd eat other bgs while they are ffying.

Eglanation The

es

14.Option (b) is correct.

Eplanation:Activated sudge micro organisms need oxygen hey oridise wastes to obtain energy for growth. Insuficient Cygen will slow down or kill off aerobic micro-organisms, take facatztive organismns work less efficiently and ultimately ad to the breakage of fiocs. It will also result in the production *te foul-smelling byproucts of anaerobic decomposition. ncient oxygen must always be sustained in the aeration

Tine

Max, Tine: 1:$ Hours

(kcal m) yr. (d) It can be divided into gross primary productivity (GPP) and net primary productivity (NPP).

>

Priary

Productivity

(a) The amount of biomass or organic matter produced per unit area over sone time by plants during photosynthesis is called primary production. (b) The primary production is expressed in terms of weight (g) or energy (kcal m). (c) Units of primary prodctivity can be expressed in a terms of dry matter produced per unit of area tor a area per for or energy unit of stored given period given period.

Gross Primary Productivity of organic matter during photosynthesis. (b) Aconsiderable amount of GPP is utilized by plants in respiration. : Net primary productivity The available bioass for the consumption of heterotrophs or herbivores and decom posers is the net primary productivity.

(a) It is the rate of production

NPP= GPP-

R

Primary productivity depends on () The plant species inhabiting a particular area. (i) Environmental factors. (ii) Availability of nutrients. (lv) Photosynthetic capacity of plants. Therefore, it varies in different types of ccosystems. (e) The annual net primary productivity of the whole biosphere is approximately 170 billion tons (dry weight) of organic matter.

(9 Of this, despite occupying about 70% of the surface, the productivity of the oceans is only $5 billion tons. The rest of course is on land. > Secondary Productivity It is the rate of formation of new organic matter by consumers.

stey

jeemsO (9n)Ln

to level

energy

10%

uonson queg

in

levels;

lost about higher

of phic

is

(heat).

90%

transfer

only

at

remaining

respiration

dead

leaves.

another stored During

as

om

such

is

detritus

fallen

or animals

present

with showspathways.

from

to and

(plants)

chain

consumer.

Level

of

producers,level.

Begins bodies

Plant-eaters,

Third Animal-eaters

passes

trophic occupied

chain producer

the

an

tertiary

in in

energy

EnergY

first

chain

place

to

Speific

at

an food

Levels

by Floy

Mind

the

ecosysterm.

Pyramid

Level

Begins

to

ccologlca

Map

with

oganism

Food

Second

the

grasshopper,

Irophic

level

Energy

level

hergy No.

of

Biomass

amid

ecosystem

level

lost

level(Plants).

trophic

trophic

is

Level

wolf

Different Trophic

energy

Tiger

of of

Pyramd

trees

Zooplankton,

Fishes,

Pyramid Second

Third

grass,

Man,

Fourth because

Trophic

Birds,

e-g.,

step

grassland

pond

upright

an

in levels

Consumer/ Phytoplankton,

Consumer/

Consumer/

ecosystem

each

e.g.,

Carnivore).

e.g,

trophic

First

grassland

in in e.g.,

tree

of

•Upright

Always

at

(Carnivore)

Upright

•Inverted

(Herbivore),

Secondary

/ Producers

heat

Tertiary

e.g,

in in e.g., e.g.,

Functional ComponentsEcosystem

as

Primary

Different

(Top COW

e-g.,

Inverted

•

Productivity

Ecosyste

DecompPosition

productivity.

ofProcess

Fragmentation

Mineralisation

•Humification •Catabolism

•Leaching

called

oxygen

composition

is •

production

of

Primary

Ary

Temperature

moisture

Availability

detritus. •Chemical

biomass

GPPR

new

Soil

consumers

•

of

NPP=

of

rate factors.

nutrients. capacity formation

that

The

by

on Depends, 5

matter

of

area.

•Photosynthetic

Environmental

of

species

Availability

of

particular

plants,

Rate Plant

•

•

of

organic

Trace

of •

•

First

KOSYSTEMS

153

It reflects only the utilisation of food for the production biomass. of consumer net rate of increase in the biomass of the It is the heterotrophs. to this productivity the food is available for the (ü) Due next tropic level. Decomposition Scan to know more about breakdown of complex It is the this topic onganic matter by decomposers into inorganic substances 1ike carbon dioxide, water and nutrients. Decompositions an (b) I: is largely Oxygen roquiring process. I Detritus (dead plant remains such as leaves, bark, fowers and dead remains of animals, including faccal matter) is the raw material for decomposition. () Detrivores: Onganisms that feed on detritus are called detritivores. Earthworms, fungi, ctc. are examples of detritivores. >

Steps in decomposition The important steps in the process of decomposition are fragnentation, leaching, catabolism, humification and

warm and moist environment favors decomposition whereas low temperature and anacrobic conditions inhibit decomposition resulting in the buildup of organic materials. A

-Nutrient immobilisation: times, the soil nutrients instead of getting mineralised, get bound with the biormass of microbes, and so by temporarily unavailable to other organisms. is This incorporation of nutrients in living microbes immobilisation. called nutrient At

Energy Flow

o

o

o

mineralisation. (2)

Fragmentation

o

It is the breakdown of detritus into smaller particles by detritivores to increases the surface area of detritus particles and makes further decomposition easier. (b) Leaching In this process, water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts. (C) Catabolism simpler ) Here, the degradation of detritus into and bacterial by place takes inorganic substances fungal enzymes. operate (ü) Fragmentation, leaching and catabolism on the detritus. simultaneously (d)

Humification humus (dark amorphous ) It is the accumulation of substance) in soil. to microbial action and () Humus is resistant very slowly. decomposes serves as a reservoir ofnutrients. (iii) Being colloidal, it

(e)

Mineralisation nutrients due is the release of inorganic some microbes. degradation of humus by

to the

Factors Infiuencing Decomposition

controlled by the chemical

is of decomposition climatic factors. and detritus Composition of The rate

Chemical composítion of detritus: rich rate is slower if detritus is The decomposition in is rich detritus quicker if in lignin and chitin and sugars. like substances nitrogen and water-soluble temperature and soll molsture: (b) Climatic factors like are the most imnportant -Temperature and soil moisture through decomposition regulate climatic factors that microbes, soil their effects on the activities of

(a)

o

o

Scan to know

more about the only source of this topic energy for all ecosystems on the carth. solar incident the Of radiation less than 50% of it Energy Flow is photosynthetically active (PAR). radiation bacteria Plants, photosynthetic and chemosyntheticfood. energy to make (autotrophs) fix solar radiant smalI Plants capture only 2-10% of the PAR and this world. amount of energy sustains the entire living energy So, it is very important to know how the solar captured by plants flows through different organisms of an ccosystem. Ecosystem obeys the first and second laws of Thermodynamics. constant. The cnergy of the ccosystem is energy to synthesize a constant supply of need They counteract the universal to the molecules they require, tendency toward increasing disorderliness.

o The sun

is

Producers

solar o The green plants in the ecosystem that capture energy are

energy and convert it into chemically bound called producers. o All organisms are dependent for their food on producers (green plants), either directly or indirectly. o In a terrestrial ccosystem, major producers are herbaceous and woody plants.

Grazing Food Chain

o A simple grazing food chain Scan to know (GFC) is depicted below: more about Goat this topic Grass Man (Producer) (Primary Consumer) (Secondary consumer) o Primary producers in an aquatic ecosystem arc phytoplankton, Food Chains & algae and higher plants. Food Webs o The energy trapped by the or the a consumer on to producer is either passed dies, organism o Death of an organism is the beginning of the detritus food chain/web.

Consumers(Heterotrophs) o These are all animals thát depend on plants (directly

o

indirectly) for their food. They include: (a) Primary Consumers • These are herbivores that feed on plants. • c.g. Insects, birds and mammals in

or

the

Oswaal CUET (UG) Chapterwise Question Bank BIOLOGY

154 ternestrial eystem and molhuses in the aquatic

o

A

() Sntary Consumets • Thse are imary camivores that feed on hrhihmeg. hg. fox, man ete. )Tertiary Consumers • h ane sodary

o

camivores that feod on

imary camivnnes >

rtus Food Chain (DFC) Rhns with dead nganic matter. ohimade un of dmmsers (sanntrophs) which are o o

o

Also, energy

than at a

gganisms eg. fungi and hacteria. hehi T mt thit nongv and nutrient rquirements by dai doadnganic matterot detritus

mns

species as such. given species may occupy more than one level in the same ccosystem at the same tropb is sparrow a example, A primary consumer tine. Fo when seeds, fruits, and peas, andla secondary consumer it et worms. whe it cats insects and In most ecosystems, all the pyramids are upright producers are more in number and biomass i than the herbivores and herbivores are more in number nd biomass than the carnivores.

o

o

digestive enzymes that break down dad and waste materials into simple, inonganic materials whh ane suhsquently ahsorbed by them. aguati Nmstem, GFC is the major conduit for

lower trophic level is always

big tree.

insects feeding

Pyramid of biomass in the sea is generally inverted because the biomass of fishes far exceeds that

phytoplankton.

o The pyramid of energy is always upright because wh enengy flows from a trophic level to the next trophic level, some energy is always lost as heat at each

aaestral

tem, a much larger fraction of doRs thrugh the DFC than through the GFC. O DRCmy he onnoted with GFC at some levels: some the ganisms ot DPC are prey to the GFC animals. crows cte) are omnivores. Se animals (achs, is Teanding rgniss biomas)

Sims ofa qs

meaud

as

the masS of living

r the mumber in a unit area. Theor is expreSsod in tems of fresh

Msunt hiomass in terms of

dry weight

is more

The

unhe of ronhic levels in the grazing food chan s rsited the transfet of cnergy follows Lindemann's 10 %w, wìch states that only 10% of tansferad to cach trophic level from the lo tghic level n sture t s pssble to have so many levels -

s

ys

rate

hebivore primry carnivore, and secondary

n the gruzing food chain.

sieds

of 2 food of pyamid

conlogcal pyramid.

Scan to know more about this topic

dues and cosumers

d vius rders ghialy. The tese

of cach pvramid

ypes

of

Ecological

Pyramids

the producers (firs tratc ive) whie the pex Teprse ertiay top-level consuners or the last

Eslapical pyrumids are ef thret rypes: Pytarmac

af

horess

Fscaicuatsonsof eergycotent, biomass cr

te

D The

(a) It does not take into account the same speci belonging to two or more trophic levels. (b) It assumes a simple food chain that seldom exists i nature. It does not accommodate a food web. (c) Saprophytes are not included in ecological pyramids even though they play a vital role in the ecosystem.

Ecological Succession: Ecological succession is the process of change in the structure of species that belongs to an ecological community over time. After a mass extinction, the time scale can be decades or even millions of years, This change Occurs orderly and sequential, parallel with the changes in the physical envinonment.

Iumbers nchude all orgaismst thut trophic level. optuc icvei Teresets a functional level, not a D

Scan to know more about

this topic

Ecological Succession

o Pioneer Species: The species that invade a bare area are o Pioneer Community: The community that is capable to invade a area bare

is known as the pioneer

community o Climar community: A community that is almost near to

o

represented

s

ste

Limitations of Ecological Pyramids

t relatiship hetween

th

O

>

called pioneer species.

> Ecoiegicsl Pyramids

Th preentin at n the fom

more

higher level.

Example of inverted pyramids includes a

Tote

at a

equilibrium with the environment is called the climar community. Sere:A sequence of ecological communities arising m an area from the initial pioneer community to the finat climax community.

Primary succession: Primary succession is a type biological and ccological succession of plant life. It occun in an environment in which a new substrate is deposite This new substrate is not having any kind of vegetation and othet onganisms, It also usually lacks onganic matter. It occurs soil in places such as land flow or area left aftera from the retreated ka glacier.

o

n

Secondary succession: Secondary succession a biological and ccological is tye succession of plant life whe takes place in a habitat that has been previously but has since been populat disturbed or damaged. For inst regions where existing vegetation has been removed to trec-telling in a woodland or destructive events (au fires). such

s

OSYSTEMS

155

Succession of plants: o

Hydrarch: A succession that begins a in water body aquatic environment is called Hydrosere or

o The natural reservoir of phosphorous is rock in the form of phosphates. o During weathering of rocks minute quantities of

or

Hydrarch Succession. Nerarch: Xerosere is a succession o of plants that are Iimited in the availability of water availability. It includes the different stages in xerarch succession. originates Xerosere in extremely dry situations such as sand i deserts, dunes, salt deserts, rock deserts, etc. 1 o In ssecondary succession, the invasion of species depends he availability of water, conditions the soil. and of environment. lt also depends on whether any seeds or other propagules are present. Because soil is already existent, the pace of succession is substantially faster, and the climax Community is reached much sooner. Succession always proceeds towards the mesic community.

phosphates get dissolved in water. o The phosphorous cycle is one of the slowest bio geochemical cycles. roots and then 0 Phosphates enter the trees through their into the food chain. o The organic wastes and dead organisms are decomposed by phosphate solubilising bacteria which release phosphorous back to the soil. o The atmospheric inputs of phosphorous through rainfall or gaseous exchange of phosphorous between organisms and the environment are negligible.

e

>

>

Nutrient cycling: A nutrient cycle is defined as the cyclic pathway by which nutrients pass through, to be recycled and reutilised. The pathway comprises cells, organisms, community and ecosystem. Importance of nutrient cycles: o It is required for the transformation of nutrients from one form to another so that it can be readily utilised by different organisms, e.g. plants cannot take atmospheric nitrogen and it has to be fixed and converted to ammonium and nitrate for uptake. o Transfer of nutrients from one place to another for utilisation, e.g. air to soil or water o Nutrient cycles keep the ecosystem in equilibrium and help in storing nutrients for future uptake o Through nutrient cycling, living organisms interact with the abiotic components of their surroundings o Nutrient recycling involves both biotic and abiotic components. The main abiotic components are air, water, and soil. o The 4 main nutrient cycles are: 1. Carbon cycle. 2. Nitrogen cycle 3. Oxygen cycle 4. Phosphorous cycle.

Carbon cycle:

o Carbon is present mainly as carbon dioxide and methane in the atmosphere. o There is a continuous exchange of carbon between biotic and abiotic components by the process of photosynthesis and

Scan to know more about this topic

Carbon Cycle respiration. is dioxide carbon O Atmospheric process of photosynthesis. fixed by plants in the release carbon dioxide during O Allthe living organisms respiration. burning the atmosphere by O Carbon is released into from carbon Organic emissions. tossil fuels and auto is products waste organisms and dead and decaying decomposition after released into the atmosphere Phosphorous cycle: Scan to know more about are important O The following the this topic steps of the phosphorous cycle: a) Weathering b) Absorption by plants c) Absorption by Animals d) Returm to the Environment Phosphorus Cycle through decomposition.

>

Ecological succession: Ecological succession is the process by which the mix of species and habitat in an area changes over time. Gradually, replace these communities one another until a climax mature community"-like a forestis reached, or until disturbance, like a fire, occurs.

o

Scan to know more about this topic

Biogeochemical Cycle in Ecosystem

Types: a) Primary Succession. b)

Secondary Succession.

> Primary Succession:

Primary succession is the succession that starts in or the lifeless areas such as the regions devoid of soil life. to sustain areas where the soil is unable Secondary Succession: o Secondary succession occurs when the primary ecosystem gets destroyed. E.g. a climax community gets destroyed by fire. It gets decolonized after the destruction. This is known as secondary ecological succession. o Carbon fixation: (balances the atmosphere) Producers pick up CO, from the atmosphere and convert it into organic compounds in the process of photosynthesis. This also gives food to others outside the ecosystem. E.g.: Tribals and migratory animals. o Pollination is a significant step in the reproduction of plants. It occurs by bees, buffer flies, birds, humans, wind, water etc. Animal depends on plants for food. The absence of these plants will naturally deprive the animal of their food which leads to death. o O, release: Producers of the ecosystem release a lot of O, during Photosynthesis. For example, Amazon rainforests are called as lungs of our planet because they produce nearly 20% O,. O

>

IMPORTANT DIAGRAMS Trophic level

No. of Individuals

TC (Tertiary consumer)

3

SC (Secondary consumer) PC (Primnary consumer)

3,54,000

PP (Primary producer)

5,842,000

Pyramid

of

708,000

umbers in a grassland ecosystem

156

Oswaal CUET (UG) Chapterwise Question

Trophic level (kg/ri)

Tropic level

1.5

PC

Dry Mass

TC

Bank

BIOLOE

Dry Mass (kg/ni)

21 PP

(Zooplankton)

4

(Phytoplankton)

SC

14.2 Inverted Pyramid

11

Pyramid level

37

PP

809

of

Biomass in Sen

Energy level

TC

14.1 Pramid of Biomass in most Ecosystems

SC PO PPL

10 J

100 J 1000 7 10,000 J

1,000,000 J of Sunlight

14.3 An idealpyramid of energy

OBJECTIVETYPE QUESTIONS [AJ MULTIPLE CHOICE 1.

Decomposers like fungi

()

Autotrophs.

(iüi) Saprotrophs. (a)

(c)

2.

(a) (b) (c) (d)

3. (a) () 4. (a) (c) 5.

QUESTIONS:

8

and bacteria are [NCERT Exemplar, Q. 1, Pg. 98] (ii) Heterotrophs. (iv) Chemoautotroph.

Choose the corect answer. iand iii (b) iand iv ii and ii (d) iand ii The process of mineralisation by microorganisms helps in the release of Inorganic nutrients from humus. Both organic and inorganic nutrients from detritus. Organic nutrients from humus. Inorganic nutrients from detritus and formation of humus.

A

Which of the following is not an example of terrestrial ecosystem? An (CUET 2022) Wetland (b) Grassland Forest (d) Desert Which is not a structural aspect the ecosystem? of Stratification (b) Diversity Productivity (d) Species composition. An inverted pyramid of biomass can be found in which ecosystem?

(a) Forest (b) Marine (c) Grassland (d) Tundra 6. Which of the following ecosystems is most productive in terms of net primary production?

(NCERT Exemplar, Q. 6, Pg. 99] (a) Deserts (b) Tropical rainforests (c) Oceans (d) Estuaries 7 Which of the following is not a producer? (a) Spirogyra (c) Volvox

[NCERT Exemplar, Q. 5, Pg. 99] (b) Agaricus (d) Nostoc

AI

(a) (b) (c) (d) 9.

(a) (c) 10.

What is the spectral range of solar radiation photosynthetic organisms are able to use in the process nf photosynthesis? Photo synthetically Reactive Radiation Photo synthetically Active Radiation Photo synthetically Deactive Radiation Photo synthetically Trapped Radiation An inverted pyramid of biomass can be found in which ecosystem? [NCERT Exemplar, Q. 4, Pg. 98] Forest (b) Marine Grassland (d) Tundra Given below is a simplified model of the phosphorus cycle in terrestrial ecosystems with four blanks. Identify the blanks A, B, C and D. (CUET 2022)

Consumers A

Soil solution

C

D

Uptake

T wenthering Run off B

(a) A: Producer, B: Litter fall. C: Rock mineral, D: Detritus. (b) A: Rock minerals, B: Detritus, C: Litter fall, D: Produces (©) A:Litter fall, B: Producer. C: Rock minerals, D: Deritus (d) A:Detritus, B: Rock minerals. C: Producers, D: Litter 21 11. Which of the following is an ecosystem service provided by a natural ecosystem? (a) Cycling of nutrients. (b) Prevention of soil erosionp (c) Pollutant absorption and reduction of the threat of globa! warming. t (d) All of the above.st nsl

COSYSTEMS

12

157

Approximately how much the of solar energy that falls on leaves of a plant is converted to chemical energy the photosynthesis? by

1%

(b) 2-10% (d) S0% where do you think the process Among the following. 1& docomposition would bec of the fastest? forest (b) Antarctic Tropical rain ) region (d) Alpine region arid i) Dry process of ecological the During succession, the changes J4 are thst take place in communities Less than

) c) 30:6

|NCERT Exemplar, Q. sequential. ) Oand Random. )

()

11, Pg. 100]

Not

influenced bby the physical environment.

E

food chain (DFC) begins with

(CUET 2022) Green plants

(b) Carnivore matter Organic (d) Herbivore Dead c) 16 The Climax community is in a state of (b) Equilibrium. (a) Non-equilibrium.

(a)

(c) Disorder.

What is the total number ecosystem?

(d) Constant change. of trophic levels of a balanced (c) 4

(b) 3

(1) 5

(d) 2

of communities of primary succession in [NCERT Exemplar, Q. 14, Pg. 100] water is () Phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and trees. rooted hydrophytes, (0) Phytoplankton, free-floating hydrophytes, sedges, grasses and trees. rooted (c) Free-floating hydrophytes, sedges, phytoplankton, trees. grasses and hydrophytes, hydrophytes, floating (4) Phytoplankton, rooted submerged and trees. meadow swamp, sedges, bydrophytes, reed sequence of 19. Which one of the following is the simplified ecosystem? a terrestrial phosphorus cycling in Consumers Rock minerals Producers (2) 18.

The sequence

Soil

Decomposers

(b) Rock

minerals

Soil

Decomposersh (c)

Rock minerals

Consumners

Producers

(c) Gaseous and scdimentary

(d) Aquatic and Gaseous was: 23. Founder of" School of Plant Ecology" in India (b) KC Mishra (a) R. Mishra (d) G.D Pant (c) RN Singh per cent of 24. Out of the total quantity of global carbon, what in oceans? carbon is found dissolved (d) 25 % (c) 90 % (b) 71% (a) 50 % 25. Round wormns in human intestine belongs to

:

(b) Trophic level 2 (a) Trophic level (d) Trophic level 4 (c) Trophic level 3 a terrestrial 26. How much of the net primary productivity of herbivores? ccosystem is caten and digested by (d) 90% (c) 40% (b) 10% (a) 1% organisms but fewest the has typically level 27. Which trophic energy? a pyramid content of energy in the highest [NCERT Exemplar, Q. 10, Pg. 99] (b) Primary consumers (a) Producers (d) Tertiary consumers (c) Secondary consumers types of ecosystem is expected 28. Which of the following precipitation, and exceeds area evaporation where in an mean annual rainfall is below 100 mm. [NCERT Exemplar, Q. 17, Pg. 101] (b) Shrubby forest (a) Grassland (d) Mangrove (c) Desert

ut

Decomposers

29. Edaphic factor refers to (a) Water.

(b) Soil. (d) Altitude. sequence correct of development of the 30. Select the (CUET 2022) he following stages in primary succession. (c) Relative humidity.

A. Scrub Stage B. Marsh-meadow stage C. Submerged free-floating plant stage D. Reed-swamp stage E. Submerged plant stage Choose the correct answer from the options given below (b) E, C, D, B, A (a) C, E, B, D, A (d) E, C, D, A, (c) D, E, B, C, A

Bia

k

Producers

Consumers Consumers Rock minerals (d) Decomposers Producers on herbivores like insects, birds and 20. The animals that feed are called mammals in terrestrial ecosystems, (CUET 2022)

consumers (b) Primary carnivores (c) Secondary carnivores (d) Primary or ocean which is altermatively * The zone at the edge ofa lake water is called exposed to air and immersed in Pg. 101] [NCERT Exemplar, Q. 18, zone (a) pelagic zone. (b) benthic zone. (c) lentic one. (d) littoral

(a) Saprotrophs

(n) Gascous and solid (b) Liquid and sedimentary

1

Very quick.

() The detritus

(CUET 2022)

22. Nutrient cycles are of two types

&

REASON:

B]ASSERTION nDirections: In the following questions,

a statement of reason (R). a assertion (a) is followed by statement of

Mark the correct choice as:

reason (R) (A) Both assertion (A) and reason (R) are true and the correct explanation of assertion (A). are true but reason (R) (B) Both assertion (A) and reason (R) e is not the correct explanation of assertion (A). t (C) Assertion (A) is true but reason (R) is false. reason (R) is true. (D) Assertion (A) is false but is

1

Assertion: The three steps in the decomposition on the (fragmentation, leaching and catabolism) operate detritus simultaneously

(UG) Chaptorwise Question Bänk

Owaal CUET

158 mineralisation occur during Reason: Humification and decomposition in the soil. serves as a reservoir of nutrients. Assertion: Humus 2. Reason: Ilumus colloidal. pyramids, the successive Assertion (A): In ccological 3. upex, levels towards the tiers represent successive tropic producers, the Reason (R): The base of the pyramid is of' are of next one above is the herbivores and the top tiers carnivores, 4.

5.

6.

7.

a level, Assertion: The tropic level represents functional not a species as such. one tropic Reason:A given species may occupy more than level in the same ccosystem at the same time or Assertion (A): Ecosystem may be natural man-made.

Reason (R): The ccosystem is a functional unit of nature. Crop-fields and aquariums mny be one of the examples of man-made ecosystems. Assertion (A): The rate of biomass production is called productivity. It is of two types: GPP and NPP. Reason (R): Gross primary productivity (GPP) is the rate of production of organic matter during photosynthesis. AI Assertion: Low temperature and anaerobiosis inhibit decomposition resulting in a buildup of organic materials Reason: Decomposition is largely an oxygen-requiring process.

8

Assertion (A): The vertical distribution ofdifferent species, which occupy diflerent levels is called stratification. Reason (R): In a forest ecosystem, trees occupy the top

9.

strata, followed by shrubs, herbs and grasses. Assertion (A): Plants capture only 2-10 per cent of the photosynthetically active radiation (PAR), Reason (R): The Sun is the only source of cnergy for all.

10. Assertion (A): Producers capture only about 1-5% of the total solar radiation. as Reason (R): Most of the solar radiation gets dissipated

heat.

JCI COMPETENCY/CASE-BASED QUESTIONS: answer the question I. Read the passage carefully and passage from 1-5. given after the All biomes of the earth constitute the earth's ecosystem. All flora and fauna occur in the lithosphere, atmosphere and hydrosphere along with their environments. Air, water, soil, biota, temperature and light are the major environmental factors that directly affect the flora and fauna in different geological areas of the earth. 1. Climate of an area depends upon: (b) Latitude of the area (a) Altitude of the area (e) Topography

(d) Both (1) and (2). 2. Hydrological cycle is concerned with: (a) Lithosphere (b) Hydrosphere (c) Atmosphere (d) All of these.

Soilaeration is inverscly proportional (a) Soil pore spaccs (b) Dianmoter of soil particles (c) Water holding capacity of soil None of the ubove. 3.

to

(d)

Edaplhology

4.

(n)

is

Soil

concemed with the study (b) Climate

of

(d) Topography following questions a ln thc a statement of Assertion (A) is followed by teason as: R corrcct choicc the Mark (A) and reason (R) arc truc amd reason (n) Both Assertion ) is the correct cxplanation of Assertion (A) (c) Biota Directions: 5.

(b) (c)

Assertion (A) and reason (R) arctrue but reason (R) (A) isnot the corrcct Cxplanation of Assertion is false Assertion (A) is truc but reason (R) Both

reason (R) is truc. (d) Assertion (A) is false but Assertion (A): Some orgarnisms like Salmon are knownto be Euryhaline.

Reason (R): Euryhalines can tolerate a wide range salinities. II. Study the following dingram and answer the questan given below 6-10. There arce different varictics of living organisms on the carth's surface. All living organisms interact among themselves and also with the physical environment surrounding them. This is a functional unit of the livin. world called an ecosystem. The physical cnvironmental factors in an ccosystem constitute the abiotic components, They are mainly of three types i.c., climatic, cdaphic, and topographic factors. 6. Who has coined the term ccosystem? (b) C. Mobius (a) A.G Tansley (c) Forbes (d) Sukachev among 7. the following is the largest Which

ecosystem? (a) Aquarium (c) Garden 8.

man-made

(b) Zoo

(d) Agro ecosystem. a Which is not structural aspect of the ecosystem?

(a) Stratification

(c) Diversity (d) Species composition. Which of the following is the most stable ecosystem

(c) Productivity

9.

(a) Ocean (c) Forest(a)

(b) Desert Mountain

10. Decomposers such as fungi and bacteria

ecosystem because they: (a) are the primary organic recyclers. (b) are the terminal energy consumers. (C) keep populations in check. (d) Both (a) and (b)

the

are vital to

BCOSYSTEMS

159

ANSWER KEY 1.(c) 11. (d)

21. (d)

A] MULTIPLE CHOICE QUESTIONS 7. (b)8. 5. (b)6. (b)

2. (a)

3. (a)

4. (c)

12. (b)

13. (a)

14. (a)

22 (c)

23. (a)

24. (b)

3. (a)

4. (a)

15. (c)

25. (c) |B]

L(6)

2. (a)

1.(d)

2. (d)

3. (c)

17.(c)

16. (b)

19. (b)

20. (d)

28. (c)

29. (6)

30. (b)

8. (b)

9.(a)

10. (a)

18. (b)

27. (d)

26. (b)

ASSERTION& REASON 7. (a) |5. (b) 6. (b)

10. (d)

9.(b)

(b)

|C| COMPETENCYICASE-BASED QUESTIONS 5. 4. (a) (a) |7. (d)8. (b)6.

(c)

|9.(a)

1. (d)

ANSWERS WITH EXPLANATION jAJMULTIPLE CHOICE QUESTIONS: 1. Option (c) is correct. Exolanation: Fungi and bacteria have been categorised as heterotrophs and saprotrophs which derive nourishment from

decaying organic matter and thercby decompose complex substances into

simpler substances.

Option (a) is correct. Frnlanation: Humus is an organic material formed by the decomposition of leaves. Microorganisms relcase inorganic nutrients from humus by thc process of mineralization. 2.

Option (a) is correct. an Eplanation: Wetland is not a terrestrial ccosystem, it is aquatic ecosystem. Rest all are examples of terrestrial ccosystems.

3.

4.

Option (c) is correct.

Eyplanation: Stratification, Diversity and species composition are all structural aspects of an ccosystem. On the other hand, at a spccific productivity is the rate of biomass accumulation aspect. a period by the ccosystem. It is functional

Option (b) is correct. producers Explanation: In a terrestrial ecosystem biomass of levels and trophic next at the is high while biomass decreases biomass pyramid of Therefore, level. it is lowest at the top biomass in a sea is upright. Contrary to this, the pyramid of biomass of fishes the or a generally inverted because 5.

lake is (consumers) exceeds that

of phytoplankton (producers). 6. Option (b) is correct. synthesis of organic Explanation: Primary production is the

dioxide. atmospheric or aqueous carbon all the plants in at which rate the is Net primary production energy; it is equal an ecosystem produce net useful chemical an rate at which the plants in lo the difference between the energy and the rate at ccosystem produce useful chemical energv during respiration. Tropical Which they use some of that net productive in terms of rainforest ecosystems are most primary production.

8.

Option (b)

Option (b) is correct. (d)that is Explanation: Organisms at options (a), (c) and Therefore, are producers. pirogyra, Volvox and Nostoc a heterotroph which is not 3aricus given under option (b) is a producer.

correct.

700nm.

Option (b) is correct. Explanation: In a terrestrial ecosystem, the biomass of next trophic producers is high while biomass decreases at the pyramid of top Therefore, level. levels and it is lowest at the pyramid of biomass to the this, biomass is upright. Contrary biomass of the because a inverted in a sea or lake is generally (producers). phytoplankton that of fishes (consumers) exceeds 9.

Option (d) is correct. Explanation: In the given simplified model of phosphorus is Detritus, cycling in a terrestrial ecosystem, the marked "A" label D and Producers is 1abel 'C' label 'B' is Rock minerals, Litterfall. represents 10.

Producers

Consumers Liter fall Detrims Decomposition

J

Soil

solution

Wenthering

Uptake Run

off

Rock

minerals

compounds from

1.

is

range of solar. radiation that Explanation: The spectral are able to use in the process photosynthetic organisms as Photo synthetically Active of photosynthesis is called as PAR and ranges from 400nm to Radiation. It is designated

11. Option

(d) is correct.

us Explanation: Functioning of our ecosystem provides soil erosion, services like cycling of nutrients, prevention of pollutant absorption and reduction of the threat of global

warming, etc. 12. Option (b) is

correct.

Explanation: Approximately 2-10% of the solar energy that falls on the leaves of a plant is converted to chemical energy by the process of photosynthesis.

Oswaal CUET(UG)

160

Option (c) is corrcct. Explanation: Nutrient cycles are of two tvnee. nutricnts occurs gaseous Gaseous cycle The exchange of in or vapour reservoir pool is an atmosphere or hydrosphere. form. e.g and Hydrogen cycle. Nitrogen: Carbon, Oxygen Sedimentary 22.

Option (a) is correct. Eyplanation: The process of decomposition occurs at a faster rate in wam and moist environments. Tropical rainforests favor these conditions and hence the process of decomposition would be the fastest in tropical rainforests. 14. Option (a) is correct. 13.

Explanation: Slow and conspicuously visible change in the specics composition of a given area is called ecological succession. A barren area is first inhabited by mosses or lichens which can survive harsh environment and modify the environment for the growth of next species. Followed by changed condition of environment smal vegetation and bushes grows and finally trees or climatic species establishes in the area. Therefore, these changes are orderly and sequential parallel with the changes in the physical environment. 15. Option (c) is correct.

Explanation: The detritus food chain begins with detritus such as dead bodies of animals or fallen leaves, which are then eaten by decomposers or detrivores. These detrivores are in turn consumed by their predators. The grazing food chain begins with producers, present at the first trophic level. The plant's biomass is then eaten by herbivores which in turm are consumed by a variety of consumers. Carnivores feed on consumers. Herbivores feed on green plants. 16. Option (b) is correct. Explanation: The climax community is top most stable species suited for the physical environment of ecological succession. Therefore, the climax community is in a state of equilibrium. 17. Option (c) is correct. Explanation: Since the amount of available energy decreases as we move to higher tropic levels very little usable energy remains after four trophic levels. That's why the food chain has only

3

to 4 tropic levels.

18. Option (b) is correct.

Explanation: As the changes in an ecological Successions are orderly, sequential parallel with the changes in the physical environment. Therefore, the sequence of communities of primary succession in water is phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses, and trees. 19. Option (b) is correct. Explanation: The phosphorous cycle starts with rock materials and ends with the decomposers. The phosphorous enters the ecosystem through rock minerals and, there is a negligible exchange of gaseous phosphorus between organisms and the environment. 20. Option (d) is correct.

Explanation: The animals that feed on herbivores like insects, birds and mammals in terrestrial ecosystems, are called primary carnivores. These are also called secondary consumers. Herbivores are primary consumers. 21. Option (d) is correct. Explanation: The littoral zone is the zone at the edge a of lake or ocean or in an aquatic habitat that is alternatively exposed to air. Therefore, light is also available and immersed in water. This coastal zone is rich in producers from surface to bottom, with a large number of brown and red algae attached to the Zone. There are different zones an aquatic ecosystem. The pelagic Zone of water in a sea or lake that is neither close to the bottom nor the shore is a zone. pelagic Benthic zone: It is the bottom Or the water body (aphotic h zone), light is not available and Microorganisms and benthic organisms are found in is dark. zone. this zone: It refers to standing or relatively still water in an aquatic ecosystem.

t

Chapterwise Question Bank BIOLOGY

A

a Sedimentary cycles are type of biogeochemica cycle Earth's is reservoir crust.e.g. Sulphur in which the cycle, and Phosphorus cycle.

23. Option (a) is correct. n Explanation: Ramdeo Misra is known as the Father of ecology in India. 24. Option (b) is correct. Explanation: Almost 71 per cent of carbon is found dissolved of quantity of; global carbon. Out in oceans out the totalper cent ofthis 71 per cent, almost 90 is found in ocean. The oceans carbon. consist of 38,000- 40,000 gigatons (Gt) of 25. Option (c) is correct. Explanation: Rounds worms are parasite of human intestine which are carnivores, thus, they belong to secondary consumer level i.e. they belong to trophic level 3. 26. Option (b) is

correct.

Explanation: About 10% of the net primary productivity terrestrial ecosystem is eaten and digested by herbivores

of

27. Ans: Option (d) is correct. Explanation: Tertiary consumers are typically at the top of the food chain and feed on secondary consumers or other tertiary consumers. While they have the highest energy content in their bodies due to consuming organisms lower in the food chain, their population is usually the smallest because there is less energy available as you move up the trophic levels. This phenomenon is known as the "pyramid of energy." 28. Option (c) is correct. Explanation: When evaporation exceeds precipitation, the soil moisture supporting vegetation will deplete and therefore growth of vegetation will cease. Hence, a desert ecosystem, where vegetation is almost nil, is expected in an area where evaporation exceeds precipitation, and mean annual rainfall is

below 100 mm. 29. Option (b) is correct.

Explanation: Locality factors or the environment of soil is described by the term Edaphic factor. 30. Option (b) is correct. Explanation: Ecological succession is the gradual change in the species composition of a given area. In primary succession in water, the pioneers are replaced with time by rooted submerged plants (submerged plant stage)-Submerged free fioating plant stageReed swamps stage-Marsh meadoW

stage-scrub stage-Forest. B]ASSERTION & REASON: I.

1.

Option (b) is correct. Explanation: The three steps in the decompostion (fragmentation, leaching and catabolism) operate detritus simultaneously. Humifcation & mineralisationOar occ during decomposition in the soil. 2. Option (a) is correct. serves Explanation: Being colloidal (organic colloid) humus as a reservoir of nutrients. 3. Option (a) is correct. Explanation: Each nourishment as of successive

level trophic represented by links of food chain is known as the level. Organisms whosethe by ne food obtained from plants

FCOSYSTEMS

161 number of steps belong to

the same trophic same level. Thus, (producers) occupy plants green the first trophic

level; plant (primary consumers) the secondary calerss level, and carnivores cat. herbivores, the third level. which

Option (a) is correct. Eplanation: The trophic level represents a functional level, .species as such. A given species may occupy not a more same ecoSystem e trophic level in the at the sarme time. than Option (b) is correct.

Eyplanation: Ecosystem may be natural or man-made. It is a functional unit of nature. Crop ficlds and aquariums may be someeexamples of man-made ecosystems.

6Option (b) is correct. Eplanation:

Gross

primary

productivity (GPP) of an of organic matter during productivity(NPP) is the amount matter stored by producers per unit area per of organic ne Gross primary productivity minus respiration lossesunitis he net primary productivity i.e., NPP=GPP-R.

the rate of production photosynthesis.. Net primary ecosystem is

Option (a) is correct.

1.

Explanation: Low temperature and aerobiosis inhibit dcomposition resulting in the building of organic materials because decomposition is largely an oxygen-requiring process. correct. &. is Option (b)

Eplanation: The vertical distribution of different species occupying different levels is called stratification. For example, trees occupy the top vertical strata or layer of a forest, shrubs the second and herbs and grasses occupy the bottom layers. Option (a) is correct.

9.

Explanation: Explanation The sun is the ultimate source of energy for all living organisms. About 1-5% of incident solar energy

or 2-10% of PAR is captured by the photosynthetic the synthesis of organic matter (Gross primary

organisms for productivity). 10.

Option (a) is correct.

Erplanation: Green plants capture about 1% of the energy of sunlight that falls on their leaves for the process of photosynthesis. This energy is converted into chemical energy as

food.

[Cj COMPETENCY/CASE-BASED QUESTIONS: 1. Option (d) is correct. Explanation: The altitude of an area can impact like climate

that is mostly rainy and have low temperature while the altitude of an area impact the ultimate with respect to the equator and

poles. 2. Option (d) is correct. Explanation: The lithosphere is concerned with land, the hydrosphere with water bodies and the atmosphere is concerned with space. The hydrological cycle circulates in allthese three

subsystems. Option (c) is correct. Explanation: More will be the water holding capacity of the soil, less will be the air spaces less soil aeration. 3.

4. Option (a) is correct. Explanation: Edaphology

is the

study of soil useful for plant

growth.

Option (b) is correct. Explanation: Euryhaline animals like salmon can adopt a wide range of salinity as they are found in areas where rivers and 5.

sea meet. 6. Option (a) is correct. Explanation: A.G Tansley in 1935 coined the term Ecosystem. 7. Option (d) is correct. Explanation: Manmade ecosystems are called Agro

ecosystems. It is an ecosystem on agricultural land.

8. Option (c) is correct. Explanation: Stratification, Diversity and species composition are all structural aspects of an ecosystem. On the other hand, productivity is the rate of bionass accumulation at a specific period by the ecosystem. It is a functional aspect. 9. Option (a) is correct. Explanation: Oceans are the most stable ecosystems. Other terrestrial ecosystems undergo changes and succession of biotic components. But oceans remain stable for a long duration of

time.

Option (d) is correct. Explanation: Decomposers are vital to the health of the ecosystem because they prevent nutrients from being tied up in one place for extended periods. 10.

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CHAPTER

15

BIODIVERSITY AND ITS CONSERVATION total of the species of

mammals.

Revision Notes: diversity (or heterogeneity) of Biodiversity: macro biological organisation ranging from cellular molecules to biomes. to Edward Wilson: Popularized the term "biodiversity' biological at levels all of diversity describe the combined organization.

o

It is the

Levels of Biodiversity o Biodiversity has been divided into three hierarchical levels of biological organization. 1.

Genetic diversity (a) Diversity shown by a single species at the genetic level. e.g., Rawolfia vomitoria in Himalaya shows genetic variation in the potency and concentration of the chemical, reserpine. and (b) India has more than 50,000 different strains of rice mango. 1,000 varieties of 2. Species diversity

(b)

species are not culturable under laboratory

o Biodiversity is not uniform throughout the worla

varies with the change in latitude and altitude, t is affected by latitudinal gradients and species-area relationship. Following are the main patterns of biodiversity. Gradients Latitudinal (a) Species diversity decreases from the equator to the It

.

poles.

• Tropics (latitudinal range

of

23.5°Nto 23.5°

S)

have more species than temperate or polar areas. • Tropical forest region like Ecuador has up to 10 times species of vascular plants as compared to forest of equal area in a temperate region like the Midwest of USA. Tropical Amazonian rain forest (South America) has the greatest biodiversity on earth. •Biodiversity (species richness) is highest in tropics because () Tropics had more evolutionary time. (less environment (ii) Relatively Constant seasonal). (ifi) They receive more solar energy which contributes to greater productivity. Species - Area Relationship

.

on

Earth (Global Species Diversity): o According to IUCN or International Union for Conservation of Nature & Natural Resources (2004) more than 1.5 million species have been described so far.

million (considering the species are to be discovered in the tropics. i.e., only 22% of the total species have been recorded so far). O Animals are more diverse (above 70%) than Plants including plantae and fungi (22%). o Most species-rich taxonomic group among animals are: Insects (70%, i.e., out of every 10 animals, 7 are insects). o Number of fungal species is more than the combined

Many

Patterns of Biodiversity

diversity.

7

totalI nnumber of prokaryotic

conditions.

3. Ecological diversity Diversity at ecosystem level. For e.g., In India, deserts, & rain forests, mangroves, coral reefs, wetlands, estuaries seen, Scandinavian whereas the alpine meadows, all can be countries (like, Norway, Sweden) have less ecological

o According to Robert May, the global estimate is about

Biologists are not sure about species because:

reptiles ani

are not suitok (a) Conventional taxonomic methods species. for identifying microbial

Diversity at the species level. e.g., Western Ghats have greater amphibian species than the Eastern Ghats.

o Number of Species

ishes, amphibians,

)

According to the study of Alexander von Humbola (German naturalist & geographer) in Sou American jungles, within a region, species richness increases with an increase in explored. area, but only up to a limit. 3

Relation between species richness and area birds, wide variety of taxa (like, angiosperm plants, freshwater fishes) gives a rectangular hyperbola.

vERSITY ANDITS CONSEHVATION

163

Rerves

•Aheipieas

take

binitt

Par

to datr

frocgants

SlIhinl

gardes

SantuarySisnhere

Pars

•Hotsps

•Natianal

hans Moral

for

•Zologial

Rtanial

care Gene dered

Consrai

USTtarian

ure drus

NstLv

ErsituCo

the

Brt

spo,

of 25%

than

of

liitaa

Narrow i

Conservaton

Biodiversty

its

More

Conseration and

SuOsead invasions

bioogical

from

to

odiversity

maomoeules Orerevpoitation

and

ranging

fragmentation

Co-extinctions

Alien-spdes

loss

level

of diversity

Habitat onganisation

ot loss

ecosystem

Bio

biodiversity

ellular biones

•

•

•

•

of Causes

The

the

ZlgA

at

Biodyersity

Diversity

elatio

+ C

Relatonship

biodiversity

s194Ipota Jo suIaneA SpeciesDiversity

oft .of sels tesio

Versit

SCA²

S

diversity

contrbuted

are

enetic

to

species

year

ace

show from

for human

in

not

variation

a

Ghats Eastern

by

survival

is

poles. lhave range

Mosses

ish,

the

Increased

diversity

biodiversity

shown

the

S) than polar

(latitudinal

23.5°

towards

to

Algae

Rautwolfia

animal

stable.

Western

in

at Diversity

Tilman:

stable

chemical

Fungi

health

higher

•Species

equator

shows

Thopics

more

other

species

e.g,-

e.g-,

more

Rich

•The

•A

•

Molluscs

Insects

of

or temperite

23.5°

Crustaceans

species

specles

N

decreases

groups

and

variation

Diversity

areas,.

from

genetic

than

s of

Importance

communities

the

at

productivity.

reserpine.

Ferns Lichens

of community

genetic

&

speies

productivity

with

allies

Windy Mamnnals

diversity

essential

moe singlelevel. vomitoria

-Reptiles

diversity

greater

have

Area

log-log

Amphibians

much

too

species

ale

Syecdes-

to

year. ecosystem

Ghats.

Area

Global

amphibian

level.

h

gradients

LatitudinaliospermsJAng

es

log

Owaal CUET (UG) Chaptenwise Question Bark

154 Loss of Biodiversity o IUCN Red List (2004) says that

>S=ca Log S =

lg C+ Z log

7S4 species (338 vertehrates, 359 invertehrates and 87 plants) the last 500 became extinct

A

BIOGY

Scan t morr this

kka

n

years. eg-. Dodo (Mauritius), Quagga (Africa), Thylacine (Australia), Stellar 's sea cow (Russia) and 3 subspecies (Bali, Java, Caspian) of the tiger.

riehnem

log-log-togscale Bpedes

D

Los sf Biodiveri

o 27 species have disappeared in the last 20 year

o

The extinctions across taxa are not random groups (like amphibians) appear to be more vulae to extinction. o More than 15,500 species are facing the thr

Area

Oalngihmic scale the relationship

sraig

is a

ne a ln, dscibed by the equatian:

log S = log C+Z log C= co-efñcient) (regression of Iine the Z=sipe range of the of0.1 to 02 The aiue Zis in among the large relationship the species-e slope of the line is the continents, Tes hike etie eg, to 0.6 12). Tane: fo fugivorous Z birâs znd mammals in the topical forests of Giñeren contnnts, the slope is 1.15. A

inS=SesicmSs,A=Area,

.

n

•

Sen

Importence of Species Diversity to the Ecosystem D

Frmzrvdecaies, ecoiogists heieved that conmunities more

mT specis, tram

WIm

genealhy, tend to be

stable

those win fea species.. Sabie commniy should not show too much year to vear, it must be 12210n in moiuctivr to occasional disturbances fe SiSant estin must aiso be resistant to and mat-made, t tztrz N2S1ns ty ziien species Devit Tinan fond tht pots wih more species sowe less ye20-vez vziaion in 10tal biomass. He 2so shwed fnat in his experiments, increased ivesty comibted 1o highe productivity. A ii biodivsity is not onty essentizl for ecosystem teattt bu inrpeztive for the surival of the human race A

m

r

r

m this pzne Stnford ecoingis: Faud Ehrich explained the efect of ioss of speis frough his rivet popper hypothesis".

Rivet pupper iyputbesis: Ths trypttesis was used by Stanford ecologis: Paul Ehrlich. joined together using thousands of i apiate. al ps zre ípcis). fevey passenge trzvelling in air plane starts PIpmg tive 1o taie home (causing a species to become eflect fiigtt safety (proper functioning of xtie), t ey oysu) intaliy, but es more and more rivets are removed, fe piates beoue dangeruusiy weak over a period of time. Loss of tives oo the wings (key species that drives major osysie futctons) is mote serious threat to flight safety ttan ss of a few rivets on the seats or windows inside

vs

o

piate.

extinction. 12% birds, 23% mammals, 32% amphibians, 31% gvmnosperm species face the threat of extincti o On earth, there have been five mass extinctin Species and at present "Sixth Extinction' is in proges o The current extinction rate is 100 - 1000 tims f than in pre-human times. If this trend continues, S0% species might be extinct within the next 100

o

the

ne

Impacts of Loss of Biodiversity (a) Decline in plant production. resistance environm to Some (b) Lowered perturbations such as drought. (c) Increased variability in ecosystem processes as plant productivity, water use and pest and disese cycles.

Causes of Biodiversity Losses (The Evil Quartet)

o "The Evil Quartet" is the phrase

coined by Jared to describe the four human induced carses Diamond

of extinction. (a) Habitat Loss and Fragmentation • It is the most important cause. For e.g. Tropic rain forests (loss from 14% to 6%). • Thousands of hectares of rain forests are being les within bhours.

• The Amazon rain forest ("lungs of

the planet

is being cut for cultivating soya beans or for the conversion of grasslands for catle. • When large habitats are broken up into smal fragments due to various human activites mammals and birds requiing lange territornes certain animals with migratory habits are bady affected, leading to population declinc. (b) Over-exploitation • The dependence of humans on nature for

n

and shelter led

to the over-exploitation

to

offnarura

resources. Example: Many species like Stellar 's sea Passenger pigeon, etc, became extinct due to exploitation. •

Many

of

work

populations around the continued endangering the species. some commercially important

marine fish

are over-harvested,

existence

0

BODVERSITY AND TS CONSERVATION

)

165

Alien Species Invasions

When alien species are introduced unintentionally deliberately, some them tum invasive, and of cause the decline or cxtinction of indigenous species. These alien species cause decline or extinction of indigenous species. . Example: (a) The Nile Perch introduced Lake Victoria (East Africa) caused extinction of more than 200 species of cichlid fish. (b) Invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eichhomia) caused damage to our native species. () The illegal introduction of the African Catfish (Clarias gariepinus) for aquaculture is posing a threat to the indigenous catfish (Clarias batrachus) 47 in our rivers. (d) Co-extinction When a species becomes extinct, the plant and animal species associated with it also become extinct. Example: (a) Extinction of the parasites takes place when the host is extinct. (b) In co-evolved plant-pollinator mutualisn extinction of one leads to the extinction of the other.

r

Conservation Processes There are three main reasons for conserving the biodiversity which are categorized as follows:

(a)

Narrowty Utilitarian Arguments Humans derive economic benefits from nature such as food, firewood, fibre, construction material,

•

industrial products (tannins, lubricants, dyes, resins, perfumes) and medicines. More than 25% of the drugs are derived from plants. 25,000 species of plants have medicinal value. Exploring molecular, genetic and species-level diversity for i.e., "bioprospecting products of economic importance may enomously benefit nations with rich biodiversity.

(b) Broadly Utilitarian Arguments

Biodiversity has many ecosystem services. in the • Amazon forest produces 20% of total 0, ofphotosynthesis. process the carth's atmosphere by • Pollination service takes place through bees, bumblebees, birds and bats. through thick • Aesthetic pleasures such as walking bloom or full in flowers woods, watching spring moming. song in the waking by hearinga bulbul's pest control, climate are • Other indirect benefits control. flood moderation and •

(c) Ethícal Arguments

value. • Every species has an intrinsic

•

care for their We have a moral duty to take being.

well

Conservation of Biodiversity Scan to know more about (a) In situ conservation (on site) this topie • It is the conservation of genetic resources within human-made natural ccosystems in which they hotspots of occur. biodiversity Protected Examples: areas such as National Parks, Sanctuaries, Biosphere reserves, cultural landscapes, national monuments.

Types of Conservation

()) National •

Park

Strictly reserved for the welfare of the wildlife where private ownership, cultivation, grazing, etc., are prohibited. There are 90 national parks in indiz.

(ii) Sanctuary Here, protection is given only to the animals. Collection of timbers, minor forest products 2nd as private ownership are allowed so long they do not harm the animals. There are 553 wildlife sanctuaries in India

(ii) Biosphere Reserves Areas of land or coastal environments to conserve the ecosystem and genetic resources contained therein. There are 18 biosphere reserves in Indi. (v) Sacred Forests (Sacred Groves) Sacred groves are highly Scan to know protected forests because more about of religious and cultural this topic traditions. Sacred groves in Khasi and Jaintia Hills in Meghalaya. Hills of Aravalli

Sacred Groves

Rajasthan.

Western Ghat regions of Karnataka & Maharashtra. Sarguja, Chanda and Bastar areas of Madhya Pradesh. In Meghalaya, the s3cred groves are the last refuges for a large number of rare and threatened plants. is It a spots: (v) Hot Scan to know biogeographic region which more about this topic Serve as significant reservoir of bio-diversity but they are threatened due to degradation, illegal logging. etc. . Biodiversity and These are the richest Conservation most threatened and the reservoirs of plant and animal life on earth. There are 36 hotspots in the world.

Oswaal CUET (UG) Chaptervise Ouuestion

166

Bark.

•

ea

In total, all the biodiversity hotspots cover less

than 2% of the carth's land area but could reduce the ongoing extinctions by almost 30%.

Three main hotspots (Western Ghats and Sri Lanka, Indo-Burma and Himalaya) cover India's biodiversity regions. (b) Ex situ conservation (off site) •. It is the conservation of organisms outside their habitats. • In this approach, threatened animals and plants are taken out from their natural habitat and placed in a special setting where they can be protected and given special care. For e.g., genetic resource centres, zoological parks, botanical gardens, gene banks etc. • In recent years, ex-situ conservatíon has advanced by preserving the gametes of threatened species in viable and fertile condition for long periods using

htt

BIoLOGT

cryopreservation techniques. eges can in-vitro, and plants can be propagated befertihsea culture methods. Seeds of different genetic strains of important plants can be kept for omnerially long perds Seed banks,

International Efforts for Conserving Biodiversity o

The Earth Summit (Rio de Janeiro, 199%92) objectives: