GAMSAT Practice Test 3 [1 ed.]

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GAMSAT Graduate Medical School Admissions Test

Practice Test 3 First edition

Contents Introduction 3 Section I: Reasoning in Humanities and Social Sciences

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Section II: Written Communication

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Section III: Reasoning in Biological and Physical Sciences

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Notes on Assessment of Written Communication

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Answers to Multiple Choice Questions

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Acknowledgements 93

First edition 2017 by the Australian Council for Educational Research Copyright © 2017 Australian Council for Educational Research

Introduction The GAMSAT Practice Test 3 contains materials and questions equivalent to the full Graduate Medical School Admissions Test, and will take approximately five and a half hours to complete if worked through under test conditions. Questions contained in Practice Test 3 are grouped, as in the live test, into three sections: Section I Reasoning in Humanities and Social Sciences Section II Written Communication Section III Reasoning in Biological and Physical Sciences As in the live test, the timing of each Section is as follows: Section I 75 questions 100 minutes Section II 2 questions 60 minutes Section III 110 questions 170 minutes You are encouraged to devote an entire day to the completion of Practice Test 3, taking a one-hour break before commencing Section III. You are strongly advised not to check your answers against the keys provided for Sections I and III until you have completed all three sections of the test. It would be beneficial to score your work and analyse any errors on the following day. By working through Practice Test 3 you will become familiar with the level of difficulty and the kind of materials found in the live test. You will also accustom yourself to the number of questions it is necessary to complete in the given timeframe. These questions should enable you to gain useful experience in the techniques of answering multiple choice questions. The writing prompts provided for Section II give you an opportunity to complete two writing tasks in a limited time. Notes on the assessment of GAMSAT Written Communication are provided on page 91. More general advice on how you can prepare for GAMSAT is contained in the GAMSAT Information Booklet, available from the address or website below:

GAMSAT OFFICE ACER Private Bag 55 Camberwell VIC 3124 Australia Email: [email protected] Web: https://gamsat.acer.org

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Section I Reasoning in Humanities and Social Sciences Questions 1 – 5 In the following passage Sigmund Freud describes his idea of ‘dream-work’. From the comparison of the remembered manifest dream-content with the latent dream-thoughts thus discovered there arises the conception of ‘dream-work’. The entire sum of the transforming processes which have changed the latent dream-thought into the manifest dream is called the dreamwork. The astonishment which formerly the dream evoked in us is now perceived to be due to the dream-work. The function of the dream-work may be described in the following manner. A structure of thoughts, mostly very complicated, which has been built up during the day and not brought to settlement – a day remnant – clings firmly even during night to the energy which it had assumed – the underlying centre of interest – and thus threatens to disturb sleep. This day remnant is transformed into a dream by the dream-work and in this way rendered harmless to sleep. But in order to make possible its employment by the dream-work, this day remnant must be capable of being cast into the form of a wish, a condition that is not difficult to fulfil. The wish emanating from the dream-thoughts forms the first step and later on the nucleus of the dream. Experience gained from analyses – not the theory of the dream – teaches us that with children a fond wish left from the waking state suffices to evoke a dream, which is coherent and senseful, but almost always short, and easily recognizable as a ‘wish fulfillment’. In the case of adults the universally valid condition for the dream-creating wish seems to be that the latter should appear foreign to conscious thinking, that is, it should be a repressed wish, or that it should supply consciousness with reinforcement from unknown sources. Without the assumption of the unconscious activity in the sense used above, I should be at a loss to develop further the theory of dreams and to explain the material gleaned from experience in dream-analyses. The action of this unconscious wish upon the logical conscious material of dreamthoughts now results in the dream. The latter is thereby drawn down into the unconscious, as it were, or to speak more precisely, it is exposed to a treatment which usually takes place at the level of unconscious mental activity, and which is characteristic of this mental level. Only from the results of the ‘dream-work’ have we thus far learned to know the qualities of this unconscious mental activity and its differentiation from the ‘fore-conscious’ which is capable of consciousness.

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In dream-work A B C D

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latent and manifest content are separated. latent and manifest content are reconciled. manifest content is changed to latent content. latent content is changed to manifest content.

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The latent content of a dream is best described as A B C D

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The function of dream-work is to A B C D

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repress wishes. settle thoughts from the day. intensify thoughts from the day. bring energy into the unconscious.

Dream-work casts a ‘day remnant’ (line 8) in the form of a wish so as to A B C D

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the residue of the day. the fore-conscious. an expressed wish. the unconscious.

disturb sleep. create energy. facilitate sleep. create a day remnant.

A ‘dream-creating wish’ (lines 16 and 17) for an adult is A B C D

evident. disguised. fragmented. indecipherable.

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Question 6 The following diagrams present performance assessments of English hospitals for: •

England as a whole

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three individual hospitals (I, II, III)

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mining and industrial areas

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prospering areas.

Health improvement

Fair access

Health improvement

Health outcomes

Effective delivery of appropriate care

Patient/care experience

Fair access

Effective delivery of appropriate care

Efficiency England Prospering areas Mining and industrial areas

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Which hospital probably focuses on caring for the terminally ill? A B C D

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I II III indeterminable

Health outcomes

Patient/care experience

Efficiency England Hospital I Hospital II Hospital III

Question 7

If you suspect a man, don’t employ him, and if you employ him, don’t suspect him. Chinese proverb

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This statement suggests that A B C D

suspicion can damage even the trustworthy. employment is an endorsement of employees. employers have to be wary of their employees. employees have to be wary of their employers.

Question 8

‘Who can refute a sneer?’ William Paley

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This statement implies that A B C D

sneering is powerful and cannot be reasoned away. it takes skilful reasoning to disarm a sneer. sneering is a powerful form of reasoning. refutation provokes sneering.

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Questions 9 – 13 The following four poems are all concerned with World War I. I

Epitaph on an Army of Mercenaries1

These, in the day when heaven was falling, The hour when earth’s foundations fled, Followed their mercenary calling And took their wages and are dead. Their shoulders held the sky suspended; They stood, and earth’s foundations stay; What God abandoned, these defended, And saved the sum of things for pay.

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A.E. Housman, 1922 1

 ercenaries: an insult directed at British soldiers, who were paid volunteers, by German soldiers, who were M unpaid

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‘They’

The Bishop tells us: ‘When the boys come back They will not be the same; for they’ll have fought In a just cause: they lead the last attack On Anti-Christ; their comrades’ blood has bought New right to breed an honourable race, They have challenged Death and dared him face to face.’ ‘We’re none of us the same!’ the boys reply. ‘For George lost both his legs; and Bill’s stone blind; Poor Jim’s shot through the lungs and like to die; And Bert’s gone syphilitic: you’ll not find A chap who’s served that hasn’t found some change.’ And the Bishop said: ‘The ways of God are strange!’ Siegfried Sassoon, 1917

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III

Glory of Women

You love us when we’re heroes, home on leave, Or wounded in a mentionable place. You worship decorations; you believe That chivalry redeems the war’s disgrace. You make us shells. You listen with delight, By tales of dirt and danger fondly thrilled. You crown our distant ardours while we fight, And mourn our laurelled memories when we’re killed. You can’t believe that British troops ‘retire’ When hell’s last horror breaks them, and they run, Trampling the terrible corpses – blind with blood.

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O German mother dreaming by the fire, While you are knitting socks to send your son His face is trodden deeper in the mud. Siegfried Sassoon, 1918

IV Another Epitaph on an Army of Mercenaries It is a God-damned lie to say that these Saved, or knew, anything worth any man’s pride. They were professional murderers and they took Their blood money and impious risks and died. In spite of all their kind some elements of worth With difficulty persist here and there on earth.

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Hugh MacDiarmid, 1935

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Which one of the following words from Poem I takes on a moral value not usually associated with that word? A B C D

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‘heaven’ (line 1) ‘mercenary’ (line 3) ‘suspended’ (line 5) ‘abandoned’ (line 7)

Based on the comments of the soldiers (‘boys’) in Poem II, which of the Bishop’s comments would the soldiers find most offensively glib? A B C D

‘they’ll have fought / In a just cause’ (lines 2 and 3) ‘their comrades’ blood has bought’ (line 4) ‘challenged Death and dared him face to face’ (line 6) ‘The ways of God are strange!’ (line 12)

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Of the following lines from Poem III, which most emphatically suggests blame? A B C D

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Which poem has the least anger in it? A B C D

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I II III IV

Which poem suggests that peaceful civilisation itself is partly the cause of the horror of war? A B C D

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‘You love us when we’re heroes’ (line 1) ‘You worship decorations’ (line 3) ‘You make us shells’ (line 5) ‘You crown our distant ardours’ (line 7)

I II III IV

Question 14 Question 14 is based on items (i), (ii) and (iii) below. (i)

Advantageous to Others

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Disadvantageous to Self

Advantageous to Self

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Disadvantageous to Others

(ii)

 rickle-down economics: the view that a benefit to the wealthy is to the benefit of the middle classes and T the poor.

(iii) Socialism: an economic, social and political doctrine which demands the equal distribution of wealth.

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A proponent of trickle-down economics would place socialism in which quadrant? A B C D

I II III IV

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Questions 15 – 20 The following passages are all concerned with understanding human history. The passages were published between the middle of the nineteenth century through to the early twentieth century. I Modern history has rejected the beliefs of the ancients without replacing them by a new conception, and the logic of the situation has obliged the historians, after they had apparently rejected the divine authority of the kings and the ‘fate’ of the ancients, to reach the same conclusion by another road, that is, to recognize (1) nations guided by individual men, and (2) the existence of a known aim to which these nations and humanity at large are tending. In historical events (where the actions of men are the subject of observation) the first and most primitive approximation to present itself was the will of the gods and, after that, the will of those who stood in the most prominent position – the heroes of history. But we need only penetrate to the essence of any historic event – which lies in the activity of the general mass of men who take part in it – to be convinced that the will of the historic hero does not control the actions of the mass but is itself continually controlled.

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II The thing itself is made present before us by an exercise of creative power as genuine as that of Nature herself … whatever be the cause, the fact is so. Poetry has this life-giving power, and prose has it not; and thus the poet is the truest historian. Whatever is properly valuable in history the poet gives us – not events and names, but emotion, but action, but life. He is the heart of his age, and his verse expresses his age.

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III Let us acknowledge unprejudicedly how every higher civilization hitherto has originated! Men with a still natural nature, barbarians in every terrible sense of the word, men of prey, still in possession of unbroken strength of will and desire for power, threw themselves upon weaker, more moral, more peaceful races (perhaps trading or cattle-rearing communities), or upon old mellow civilizations in which the final vital force was flickering out in brilliant fireworks of wit and depravity. At the commencement, the noble caste was always the barbarian caste: their superiority did not consist first of all in their physical, but in their psychical power – they were more complete men (which at every point also implies the same as ‘more complete beasts’). IV If we are to draw any useful lines of demarcation in the continuous flux of history we must not scruple to say that, in the realm of knowledge and thought, modern history begins in the seventeenth century. Ubiquitous rebellion against tradition, a new standard of clear and precise thought which affects even literary expression, a flow of mathematical and physical discoveries so rapid that ten years added more to the sum of knowledge than all that had been added since the days of Archimedes, the introduction of organised co-operation to increase knowledge – characterise the opening of a new era.

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Which passage is most concerned with communication? A B C D

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I II III IV

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Which passage is most passionate? A B C D

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Which of the following concepts is most central to the argument in passage III? A B C D

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I II III IV

The last sentence of passage I (lines 8–10) suggests that the writer believes his conclusion is A B C D

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wit power nobility civilisation

Which passage is least concerned with the causes of history? A B C D

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I II III IV

provisional. self-evident. controversial. revolutionary.

Which passage is most optimistic? A B C D

I II III IV

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Questions 21 – 24 The following passage is from an essay on George ‘Beau’ Brummell, arbiter of fashion and good taste in London in the late eighteenth and early nineteenth centuries. The Duchess of –– was there, escorting her young daughter, Lady Louisa. The Duchess caught sight of Mr. Brummell, and at once warned her daughter that if that gentleman near the door came and spoke to them she was to be careful to impress him favourably, ‘for’, and she sank her voice to a whisper, ‘he is the celebrated Mr. Brummell’. Lady Louisa might well have wondered why a Mr. Brummell was celebrated, and why a Duke’s daughter need take care to impress a Mr. Brummell. And then, directly he began to move towards them, the reason of her mother’s warning became apparent. The grace of his carriage was so astonishing; his bows were so exquisite. Everybody looked overdressed or badly dressed – some, indeed, looked positively dirty – beside him. His clothes seemed to melt into each other with the perfection of their cut and the quiet harmony of their colour. Without a single point of emphasis everything was distinguished – from his bow to the way he opened his snuff-box, with his left hand invariably. He was the personification of freshness and cleanliness and order. One could well believe that he had his chair1 brought into his dressing-room and was deposited at Almack’s2 without letting a puff of wind disturb his curls or a spot of mud stain his shoes. When he actually spoke to her, Lady Louisa would be at first enchanted – no one was more agreeable, more amusing, had a manner that was more flattering and enticing – and then she would be puzzled. It was quite possible that before the evening was out he would ask her to marry him, and yet his manner of doing it was such that the most ingenuous debutante could not believe that he meant it seriously. His odd grey eyes seemed to contradict his lips; they had a look in them which made the sincerity of his compliments very doubtful. And then he said very cutting things about other people. They were not exactly witty; they were certainly not profound; but they were so skilful, so adroit – they had a twist in them which made them slip into the mind and stay there when more important phrases were forgotten. 1 2

c hair: sedan-chair, carried by porters Almack’s: a ‘social club’ for persons of fashion

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Lines 4 and 5 suggest that Louisa felt a little A B C D

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guilty. indignant. embarrassed. apprehensive.

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Lines 7–10 suggest that a key element in Brummell’s ‘grace’ was A B C D

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The image of the ‘chair’ (line 12) contributes to the portrayal of Brummell by introducing an element of A B C D

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virility. restraint. athleticism. a genuine desire to please.

absurdity. solemnity. informality. gentle humour.

Lines 14–22 suggest that Lady Louisa found Brummell’s conversation A B C D

inspiring. less than impressive. alien and intimidating. novel and disconcerting.

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Questions 25 – 28 The following passage is from a fictional work by a Christian convert. A senior devil tells a junior devil how to corrupt a human (the ‘patient’), who is feeling dispirited following his recent and exciting conversion to Christianity. I have always found that the Trough periods of the human undulation provide excellent opportunity for all sensual temptations, particularly those of sex. This may surprise you, because, of course, there is more physical energy, and therefore more potential appetite, at the Peak periods; but you must remember that the powers of resistance are then also at their highest. The health and spirits which you want to use in producing lust can also, alas, be very easily used for work or play or thought or innocuous merriment. The attack has a much better chance of success when the man’s whole inner world is drab and cold and empty. You are much more likely to make your man a sound drunkard by pressing drink on him as an anodyne when he is dull and weary than by encouraging him to use it as a means of merriment among his friends when he is happy and expansive. But there is an even better way of exploiting the Trough; I mean through the patient’s own thoughts about it. As always, the first step is to keep knowledge out of his mind. Do not let him suspect the law of undulation. Let him assume that the first ardours of his conversion might have been expected to last, and ought to have lasted, forever, and that his present dryness is an equally permanent condition. Having once got this misconception well fixed in his head, you may then proceed in various ways. It all depends on whether your man is of the desponding type who can be tempted to despair, or of the wishful-thinking type who can be assured that all is well. The former type is getting rare among humans. If your patient should happen to belong to it, everything is easy. You have only got to keep him out of the way of experienced Christians (an easy task now-a-days), to direct his attention to the appropriate passages in scripture, and then to set him to work on the desperate design of recovering his old feelings by sheer will-power, and the game is ours. If he is of the more hopeful type your job is to make him acquiesce in the present low temperature of his spirit and gradually become content with it, persuading himself that it is not so low after all. In a week or two you will be making him doubt whether the first days of his Christianity were not, perhaps, a little excessive.

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In the first paragraph, the senior devil explains to the junior devil A B C D

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An ‘appropriate’ passage of scripture (line 19) would be one that A B C D

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that it is counterproductive to try to use the patient’s happiness against him. how to break down the patient’s resistance when it is at its strongest. that it is futile to target the patient while he is miserable. how to take advantage of the patient while he is happy.

gave the patient a false sense of piety and security. made the patient strive for goals he was incapable of achieving. made the patient believe that his faith was growing ever stronger. allowed the patient to remain unaware of his growing disillusionment.

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The junior devil is warned to keep the patient away from ‘experienced Christians’ (line 18) because experienced Christians might show the patient A B C D

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how to maintain his faith without needing to question it. how to avoid temptations that lead to a loss of faith. that questioning one’s faith is natural and inevitable. that not all temptations are damaging.

The purpose of the passage is to A B C D

show readers that spirituality can be lively and humorous. expose the superficiality of conventional religion. confront readers with their lack of faith. alert readers to spiritual dangers.

Question 29

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The joke in the cartoon is that the doctor is A B

distracted. uncaring.

C D

fixated. blunt.

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Questions 30 – 34 The following passage is taken from an article about the evolution of the ‘mad scientist’ as a figure in literature. Of course, Victorians were not the first to correlate genius and mental illness. This association began with classical authors, notably Plato, Seneca, and Aristotle, who famously declared that ‘no great genius has ever been without some touch of madness’. ‘Genius’ is in fact a Latin word derived from the Greek ginesthai (‘to be born or created’). In classical pagan tradition, a ‘genius’ referred to the guiding or tutelary spirit allotted to each person at birth. From the Renaissance until the eighteenth century, English authors frequently invoked the older meaning of genius as tutelary spirit. This usage gradually gave way in the nineteenth century to the now familiar definition of genius as superlative intellectual ability (or a person possessing such ability). Significantly, the period when this linguistic transition occurred – the late eighteenth and early nineteenth centuries – witnessed the birth of several modern myths about genius. Whereas Enlightenment authors described the genius as directly inspired by God, Romantics developed a secularized version of this view that emphasized the artist or poet himself as a godlike figure. Politically, the Romantic genius was a rebellious figure who challenged social hierarchies by suggesting that innate creative powers trump class status. Romantics embraced the classical notion of the creative process as an inherently irrational furor poeticus: an ‘aesthetic response [that] seemed to involve a spell, a rapture, a delirium, a momentary madness’. The creative process was also inherently solitary and necessitated a certain degree of suffering for one’s art. In England, the Romantic figure of the godlike yet tormented genius was memorably embodied by Lord Byron’s self-loathing protagonists, the eponymous hero1 of Percy Shelley’s ‘Prometheus Unbound’, and Mary Shelley’s Victor Frankenstein. Whereas the Romantics saw genius as a mystical phenomenon beyond the reach of scientific investigation, Victorians brought scientific tools and techniques to bear on superlative ability. Rather than glorifying creative powers, Victorians pathologized genius and upheld the mediocre man as an evolutionary ideal. Michel Foucault has discussed how the impetus towards medical and social conformity reasserted itself as the Romantic cult of individuality waned; nineteenth-century scientists ‘embrace[d] a knowledge of healthy man … and a definition of the model man’. This emphasis on normalcy derived partly from Belgian mathematician Adolphe Quételet’s influential statistical concept of the ‘homme moyen’ or average man. Quételet’s essay A Treatise on Man and the Development of his Faculties (1835) presented his so-called ‘average man’ as the central value around which measurements of a human trait are grouped according to the normal distribution. According to this model, all aberrations from the norm could be seen as pathological, including extreme intelligence. 1

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eponymous hero: a character after whom a narrative is named

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In lines 1–3 the writer claims that the Victorians and classical tradition both correlated genius with madness. The discussion in lines 3–8 A B C D

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serves to demonstrate this claim. serves to invalidate this claim. fails to illustrate this claim. is essential to this claim.

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According to the passage, the Victorians saw the behaviour of the Romantic ‘godlike yet tormented genius’ (line 18) as A B C D

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According to the passage, Victorian culture represented genius as A B C D

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an affectation. a medical condition. a form of divine inspiration. a consequence of social conditioning.

According to the passage, the ‘linguistic transition’ (line 9) of the term ‘genius’ represents a change from A B C D

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instinctive. inexplicable. deviant. creative.

rebellion to obedience. pessimism to optimism. externality to autonomy. inspiration to revelation.

The passage implies that the Romantic view of genius ‘as a mystical phenomenon beyond the reach of scientific investigation’ (lines 21 and 22) is A B C D

broadly compatible with the classical view. broadly compatible with the Victorian view. basically incompatible with the classical view. basically incompatible with the Renaissance view.

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Questions 35 – 40 This passage is from an article which critically examines ‘human rights’. Alexis de Tocqueville1 combined a liberal, humanitarian perspective on political and social issues with support for the violent conquest, domination, and civilization of Algeria. In brief, the liberal discourse of human rights developed in a context in which some people are not ready to be free and others must be ‘forced to be free’, and where the path to freedom consists of open-ended domination. Liberal theory thus has included, perhaps from its inception, a particular stance toward governing people deemed incapable of having equal rights or of being full participants in political life. Another way of making this point is simply to acknowledge that a host of writers operating from a variety of critical and post-colonial perspectives has made clear that we cannot pretend rights discourse and the liberal individualism it rests upon are neutral, universal, or necessarily separate from western economic and political dominance – whether as a matter of history or of contemporary realities. Nor can we even say that liberal rights are in fact liberating in some objective sense, even for those who have them. To the contrary, liberalism and the idea of rights developed hand-in-hand with and in dependence upon colonialism, imperialism, and modern systems of production and trade, and they serve the interests of the modern state. Related to this point is the problem of exceptions. Under liberal theory, and despite the claim that everyone should be treated, in Holmes’ formulation2, as an abstract and equal rights holder, the fact remains that not everyone has equal rights all of the time. But, precisely because all people are supposed to have the same rights, those who have fewer rights must be defined as not ready for rights – as I discussed above – or in more extreme cases as subhuman. Another strategy is simply to define people as having rights despite the fact that their lived experience suggests they do not, and this last category threatens to be quite capacious in the modern world. 1 2

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Alexis de Tocqueville: (1805–1859) French political thinker and historian Holmes: Stephen Holmes (1948–), American writer and Professor of Law

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The writer uses the example of ‘Alexis de Tocqueville’ (lines 1 and 2) to argue that, from its inception, liberal theory A B C D

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In the first paragraph (lines 1–6), the writer presents ‘liberal theory’ as A B C D

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was applied in different ways to different people. placed the needs of the individual above the needs of society. viewed the needs of society and the needs of the individual as equivalent. was applied in the same way to all people, regardless of their actual needs.

an obsolete political experiment. a curious political paradox. a well-balanced philosophical theory. an unaccountable moral conundrum.

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In the second paragraph (lines 7–14), the writer argues that liberal rights A B C D

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are irrelevant anachronisms which society has largely outgrown. represent the moral foundation upon which a just society can be based. are specific social constructions designed to perpetuate that society’s ends. have been in conflict with more powerful social forces since their inception.

‘Nor can we even say that liberal rights are in fact liberating in some objective sense, even for those who have them’ (lines 11 and 12). Here the writer is suggesting that liberal rights A B C D

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are often unwanted. are often taken for granted. involve unexamined obligations. involve unfathomable obligations.

How does the writer portray the reaction of liberal theorists to the fact that ‘not everyone has equal rights all of the time’ (line 17)? Liberal theorists try to A B C D

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confront weaknesses in their theory by re-evaluating its function. avoid unwanted interpretations of their theory by increasing its transparency. simplify their theory to generate uncertainty as to what rights people have. disguise inequities in the application of their theory by altering its boundaries.

‘Another strategy is simply to define people as having rights despite the fact that their lived experience suggests they do not’ (lines 19 and 20). The writer considers this ‘strategy’ to be A B C D

disingenuous. unenforceable. deliberately divisive. an unfortunate necessity.

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Questions 41 – 45 The following passage is from a science-fiction novel. The ‘newts’ to which the speaker refers are lizard-like creatures about a metre in length. Alongside these experiments, my assistant, Herr Doktor Walter Hinkel, examined the newts to ascertain whether they could be a source of useful raw materials. We were interested in particular to ascertain whether the body of a newt contains a large quantity of iodine or phosphorus; and our positive results suggest it might be possible to extract these important elements on an industrial scale. The skin of a newt in its natural state does not have any serious use; it can however be ground to a paste and subjected to high pressure to create an artificial leather which is light and strong enough to offer a serious alternative to leather from the hides of cattle. Because of its repulsive odour, the fat in a newt’s body is of limited use, but its very low freezing temperature makes it of possible value as a lubricant for machinery. The meat of a newt was likewise considered unusable, and even as poisonous; if consumed in its raw state it causes serious pains, vomiting and sensory hallucinations. However, after a large number of experiments conducted on himself, Dr Hinkel was able to ascertain that these harmful effects disappear if slices of the meat are steamed (in this way it resembles certain mushrooms), thoroughly rinsed, and soaked for twenty-four hours in a weak solution of hypermanganese. It can then be boiled or steamed and tastes like poor quality beef. In this way we consumed the newt whom we had come to know as Hans; Hans was an educated and intelligent animal with a special talent for scientific work; it had worked in Dr Hinkel’s department as a laboratory assistant and could even be trusted with delicate chemical analyses. We would spend entire evenings talking with Hans, who enjoyed boundless curiosity. It became unfortunately necessary to dispose of Hans when he became blind following my experiments with trepanation.1 Hans’s meat was dark and with a slight flavour of mushrooms, but left no unpleasant effects. There is no doubt that in the event of need arising from war it would be possible to use newt meat as a cheap substitute for beef. 1

trepanation: operation in which the brain is exposed by means of holes bored into the skull

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The first two sentences of the passage (lines 1–5) are A B C D

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The transformation of ‘the newt whom we had come to know as Hans’ (line 15) A B C D

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overtly satirical. deceptively bland. vaguely disconcerting. self-consciously defensive.

was systematic and inexorable. resulted in a range of valuable products. could not be replicated on an industrial scale. resulted in a deeper understanding of human physiology.

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The speaker’s comment on the ‘experiments with trepanation’ (line 19) suggests that he A B C D

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Which of the following best sums up the main concern of the passage? A B C D

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enjoyed them. regretted them. had doubts about their usefulness. performed them as a matter of course.

‘the banality of evil’ – Hannah Arendt ‘power, like a desolating pestilence’ – Shelley ‘man’s inhumanity to man’ – Robert Burns ‘those who call evil good and good evil’ – Bible

The passage attacks its target by A B C D

ridiculing scientific jargon. twisting the logic of scientific discovery. invoking the stereotype of the mad scientist. appropriating the language of scientific objectivity.

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Questions 46 – 49 The following two poems were written in 1901, towards the end of the poet’s life. He recollects a woman to whom he had been close some twenty-five years earlier. Poem I She was too kind, wooed too persistently, Wrote moving letters to me day by day; The more she wrote, the more unmoved was I, The more she gave, the less could I repay. Therefore I grieve, not that I was not loved, But that, being loved, I could not love again. I liked, but like and love are far removed; Hard though I tried to love I tried in vain. For she was plain and lame and fat and short, Forty and over-kind. Hence it befell That though I loved her in a certain sort, Yet did I love too wisely but not well. Ah! had she been more beauteous or less kind She might have found me of another mind.

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Poem II And now, though twenty years are come and gone, That little lame lady’s face is with me still; Never a day but what, on every one, She dwells with me, as dwell she ever will. She said she wished I knew not wrong from right; It was not that; I knew, and would have chosen Wrong if I could, but, in my own despite, Power to choose wrong in my chilled veins was frozen. ’Tis said that if a woman woo, no man Should leave her till she have prevailed; and, true, A man will yield for pity, if he can, But if the flesh rebels what can he do? I could not. Hence I grieve my whole life long The wrong I did, in that I did no wrong.

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Samuel Butler

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Which of the following best characterises the difference in emotional quality between lines 1 and 9 of poem I? A B C D

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line 1 candid sympathetic exasperated optimistic

line 9 evasive unsparing wry resigned

47

Read in the light of poem I as a whole, the word ‘kind’ (lines 1, 10 and 13) emphasises the woman’s A B C D

48

In lines 11–14 of poem II, the poet A B C D

49

irritating intensity. generosity of spirit. physical innocence. emotional vulnerability.

condemns his lack of sensitivity. sees the woman in a radically different light. suggests that he could have overcome his aversion if he had tried. feels morally responsible for the consequences of a physical aversion.

Which one of the following is a plausible criticism of the emotional content of poem II? The poet A B C D

is detached and distant. tends to idealise human relations. ignores the reality of his own needs. is more interested in himself than the woman.

25

Questions 50 – 54 The following passage discusses principles of proof in legal tribunals in medico-scientific cases. Generally in courts and tribunals, it is the party who makes a claim or allegation who must establish the factual basis to their claim. And they must do this to a specific standard of proof. In criminal cases, the standard of proof is ‘beyond reasonable doubt’. In civil cases, the standard is ‘the balance of probabilities’. Generally for tribunals, unless the rules or governing legislation state otherwise, the standard of proof is one of ‘reasonable satisfaction’ but this obligation is variable, depending on the seriousness of the allegations or consequences of an adverse finding. Moreover, the standard can be difficult to apply where a tribunal is making its own investigations or relying on its own expert knowledge. When a tribunal is considering the medico-scientific criteria of proof, it must bear in mind that a medical possibility of causation can allow a decision-maker to find causation proved as a probability in all the circumstances. The most important legal decision on this question was given in the context of medico-scientific evidence about renal cell carcinoma from exposure to asbestos. In Seltsam Pty Ltd v McGuiness, Chief Justice Spigelman in the New South Wales Court of Appeal made it clear that: … evidence of possibility, including epidemiological studies, should be regarded as circumstantial evidence which may, alone or in combination with other evidence, establish causation in a specific case. Circumstantial evidence of disease causation would include medico-scientific evidence about general causation, which we will discuss shortly. If this evidence amounts to more than a possibility, then causation can be found proved on the balance of probabilities or even higher standards. So decision-makers can find causation proved to this standard where there is scientific uncertainty or ‘significant scientific dispute’ about the cause of a disease. The reason for this is clear. The decision-making process in a tribunal is limited by its very nature: … limited in its ambition to find the ultimate or abstract truth, and limited in the factfinding process. The [tribunal] is constrained by various pragmatic and systemic fetters such as the rules of [procedural fairness], and the need for a decision. Courts, [tribunals] and the law generally aim to achieve the correct social result rather than to determine the abstract truth, as scientists do.

50

The standard of ‘beyond reasonable doubt’ (line 3) is best described as A B C D

26

lower than both reasonable satisfaction and balance of probabilities. higher than both reasonable satisfaction and balance of probabilities. lower than reasonable satisfaction, but higher than balance of probabilities. the same as balance of probabilities and reasonable satisfaction.

5

10

15

20

25

51

The decision of Chief Justice Spigelman is important because it A B C D

52

The writer makes the point that ‘scientific uncertainty’ (line 21) A B C D

53

results in legal uncertainty. does not prevent legal certainty. is the same as legal uncertainty. is different from legal uncertainty.

The writer suggests that the ‘decision-making process in a tribunal’ (line 23) is A B C D

54

implies that possibility can be taken as proof. implies that possibility cannot be taken as proof. distinguishes circumstantial evidence from causation. implies that causation requires circumstantial evidence.

constrained by inevitable uncertainty. constrained by the need for decisions. concerned with results rather than causes. concerned with concrete rather than abstract truth.

The writer sees the legal decision-making process as ‘limited by its very nature’ (lines 23 and 24) because it is A B C D

not concerned with truth. limited to matters of fact. not limited to matters of fact. making decisions in uncertainty.

27

Questions 55 – 57 It is well known that prevalence and incidence rates of cardiovascular disease (CVD) and CVD risk factors are not equally distributed among socioeconomic groups. Known risk factors account for part, but not all, of unequally distributed CVD rates. Socioeconomic conditions and psychosocial dynamics may explain another part of the increased CVD rates. Theoretically, it may be possible to lower CVD rates and CVD risk factor prevalence among lower socioeconomic status (SES) groups by using a community development (socioenvironment) strategy directed towards changes in socioenvironmental risk conditions and psychosocial risk factors, rather than CVD risk factors per se. This article describes a protocol for such a strategy based upon the planning work of Canadian health professionals, loosely organised under a project titled ‘Heart Health Inequalities in Canada’. This protocol incorporates baseline data on CVD and CVD risk factor prevalence, but is premised on actions negotiated between community organisations and health authorities, rather than defined unilaterally by health authorities. As such, program design, activities and evaluation will differ from a more general, population-based risk factor reduction strategy.

Physiological risk factors • hypertension • hypercholesterolemia • genetic (inherited) factors

CVD mortality/morbidity

Behavioural risk factors • smoking • poor nutrition • physical inactivity Psychosocial risk factors • isolation • lack of social support • poor social network • low self-esteem • high self-esteem • low perceived power

According to the passage, A B C D

28

10

All-cause mortality/morbidity

Risk conditions • poverty • low education/occupation status • dangerous, stressful work • dangerous, polluted environment • discrimination (sexism, ageism, racism, etc.) • low political-economic power • large gaps in income/power within a community, state, nation

Figure 1

55

5

risk factor reduction strategies do not affect CVD rates. physiological risk factors do not differ between different SES groups. risk factor reduction strategies affect different SES groups differently. physiological risk factors do not completely account for different CVD rates.

56

The activity reported in the passage is concerned to A B C D

57

include a wider range of risk factors in dealing with CVD. see whether CVD risk factors are equally distributed. see why CVD risk factors are unequally distributed. focus on the risk factors of CVD for individuals.

The passage suggests that most CVD treatment is A B C D

aimed at personal empowerment and political action. a form of community organisation and health advocacy. determined by professionals with the involvement of the recipients. determined by professionals without the involvement of the recipients.

Question 58

58

The joke of the cartoon is that the speaker A B C D

is unable to associate his behaviour with capitalism and globalisation. does not intend to change his opinions on capitalism and globalisation. is attempting to impress the pamphleteer but is saying the wrong thing. does not agree with the pamphleteer about capitalism and globalisation.

29

Questions 59 – 62 The following passage is from a journal article on hypochondria. The passage begins with an extract from a novel. He had removed his trousers and was putting on the bottom half of the suit when he noticed a small oval of puffed flesh on his hip, darker than the surrounding skin and flaking slightly. His stomach rose and he was forced to swallow a small amount of vomit which appeared at the back of his mouth. Cancer. Mark Haddon, A Spot of Bother This is an essay about reading. Much as we read the page and the content of a written text, we read our bodies, looking at them as if from outside ourselves at the same time as we feel them as if from within, until we find a meaningful interpretation that fits the evidence. In each case, though, absolute verification is elusive. We must continue to read, as confidently as we can, in the face of hermeneutic1 anxiety. George, the main character in the Mark Haddon novel cited above, is a reader who is both profoundly anxious and excessively confident. Interpreting the skin lesion to mean that he has cancer provokes anxiety, but the reading itself is sure and unquestioning. He does not doubt the self-diagnosis that emerges as, and from, both a (quite literal) gut reaction and a rapidly reasoned set of deductions drawing on what he already knows or believes about lesions and illness prevention and diagnosis and skin cancer. The anxiety of interpretation arises later, when his doctor tries to reassure George that the lesion is benign. ‘Discoid eczema, unless I’m very much mistaken,’ says the doctor. ‘A week of steroid cream should sort that out.’ A hypochondriac finds this alternate reading of his body difficult to accept, for contradictory interpretations produce the worrisome hermeneutic complexity that appears to characterize hypochondria as a way of knowing – in particular, a way of reading. After initial relief, George dwells not on the benign diagnosis but on the doctor’s phatic locution2, intended to convey confidence but taken literally by George as an opening for uncertainty: ‘unless I’m very much mistaken’. As with the close reading of poetry, overly vigilant attention to one’s body risks reading too much into it, finding things that are not there. Close reading, as a particular methodology of literary criticism, might then offer a model for apprehending the (general) patient not as a body containing organs where pathologies might lurk, but as a textual representation of that body, not pinned open and dissected, but lived in. It is an approach that expects ambiguity. 1 2

hermeneutic: interpretive phatic locution: speech used to make social contact, without necessarily conveying a particular meaning

59

The extract from the novel (lines 1–5) is included because it illustrates the A B C D

30

torment of uncertainty. anxiety of interpretation. finality of absolute verification. pathology of misdirected confidence.

5

10

15

20

25

60

Because of the way they ‘read’ their bodies (line 7), hypochondriacs A B C D

61

subvert their own interpretations. lack respect for doctors’ opinions. tend to resist reassurance. tend to be hostile to treatment.

A hypochondriac who thinks she has disease X visits her doctor. Which of the following statements by the doctor would most readily induce a state of ‘hermeneutic complexity’ (lines 19 and 20) in the patient? A B C D

62

‘I’m sorry to have to tell you this, but you have contracted X.’ ‘Your travel history suggests that you have been exposed to X.’ ‘Good news: you can’t possibly have X because you’re immune to it.’ ‘Don’t worry; it’s extremely unlikely that your symptoms are related to X.’

In comparing the hypochondriac’s self-diagnosis with a ‘close reading of poetry’ (line 24), the writer is suggesting that hypochondriacs A B C D

interpret selectively. are not interested in input from others. are typically unable to make up their minds. look for the simplest possible interpretation consistent with the facts.

31

Questions 63 – 67 The passage below is from a novel. Miss Hare has lived all her life in a ramshackle mansion called Xanadu on the edge of an Australian country town. Now that she is growing old she has hired a housekeeper who will arrive the next day. A housekeeper though was less formidable than a person, and this was what Miss Hare dreaded most: an individual called Mrs Jolley, whose hips would assert themselves in navy blue, whose breathing would be heard, whose letters would lie upon the furniture addressed in the handwriting of daughters and nieces, telling of lives lived, unbelievably, in other places. It was frightening, frightening. Miss Hare often cried in private, not from grief, but because she found it soothing, and she did now. It was frightening though. Naturally she found it impossible to like human beings, if only on account of their faces, to say nothing of their habit of relating things that had never happened and then believing that they had. Children were perhaps the worst, because they had not yet grown insincere, and insincerity does blunt the weapons of attack. Possible exceptions were those children who grew up in one’s vicinity, almost without one’s noticing, just being around; that was delicious, like air. Best of all Miss Hare liked those who never expected what they would not receive. She liked animals, birds, and plants. On these she would expend her great but pitiable love, and because that was not expected it ceased to be pitiable. Once, it was related, a naked nestling had fallen into her lap, and she had reared it by some mysterious method of her own, warming it down her front, it was suspected, and ejecting juices into its beak from her mouth. The nestling had grown into a dove. Some of the Godbold children had been shown it. Then it flew away, of course, but would return sometimes, Miss Hare told. She would talk to it. Everybody except the Godbold kids thought it a lot of rot, Miss Hare talking to birds. But you could learn, she insisted. Miss Hare said you could learn to do anything provided you wanted to, but there were an awful lot of things you didn’t want enough. Like learning to love a human being. Like the housekeeper, whom the telegram and her own increasing infirmity were bringing to Xanadu. ‘Ah, no, no, no!’ she protested and whimpered in the cold early morning air. And the house repeated it after her.

63

For Miss Hare, Mrs Jolley most significantly represents A B C D

32

emotional contact. conformity and authority. a physical threat. youthful energy.

5

10

15

20

25

64

For Miss Hare, the world beyond Xanadu was A B C D

65

The passage suggests that Miss Hare’s love was thought to be ‘pitiable’ (line 13) because A B C D

66

her love was one-sided, making her experience incomplete. she knew that other forms of love would elude her. her love was openly passionate and immature. she sought love through grief.

What does the passage suggest about Miss Hare and her world of Xanadu? A B C D

67

something intriguing yet threatening. a manifestation of superficiality and material greed. something to be sheltered from that was of no interest to her. a constraint from which she had escaped but wanted to rediscover.

She sees her world as forbidding and punitive. She acknowledges only the positive side of her world. She has constructed a world that always agrees with her. She has chosen an existence that she finds unremittingly oppressive.

The viewpoints of the narrator and Miss Hare A B C D

set up a pervading dissonance. alternate predictably. compete for supremacy. modulate into each other.

33

Questions 68 – 73 The following passage is from a review by the linguist Noam Chomsky of B.F. Skinner’s Beyond Freedom and Dignity, first published in 1971. Let us now turn to the evidence that Skinner provides for his extraordinary claims: e.g., that ‘an analysis of behavior’ reveals that the achievements of artists, writers, statesmen, and scientists can be explained almost entirely according to environmental contingencies; that it is the environment that makes a person wise or compassionate; that ‘all these questions about purposes, feelings, knowledge, and so on, can be restated in terms of the environment to which a person has been exposed’ and that ‘what a person “intends to do” depends on what he has done in the past and what has then happened’; and so on. According to Skinner, apart from genetic endowment, behavior is determined entirely by ‘reinforcement’. To a hungry organism, food is a positive reinforcer. This means that ‘anything the organism does that is followed by the receipt of food is more likely to be done again whenever the organism is hungry’; but ‘Food is reinforcing only in a state of deprivation’. A negative reinforcer is a stimulus that increases the probability of behavior that reduces the intensity of that stimulus; it is ‘aversive’, and, roughly speaking, constitutes a threat. A stimulus can become a conditioned reinforcer by association with other reinforcers. Thus money is ‘reinforcing only after it has been exchanged for reinforcing things’. At this point an annoying, though obvious, question intrudes. If Skinner’s thesis is false, then there is no point in his having written the book or our reading it. But if his thesis is true, then there is also no point in his having written the book or our reading it. For the only point could be to modify behavior, and behavior, according to the thesis, is entirely controlled by arrangement of reinforcers. Therefore reading the book can modify behavior only if it is a reinforcer, that is, if reading the book will increase the probability of the behavior that led to reading the book (assuming an appropriate state of deprivation). At this point, we seem to be reduced to gibberish. A counterargument might be made that even if the thesis is false, there is a point to writing and reading the book, since certain false theses are illuminating and provocative. But this escape is hardly available. In this case, the thesis is elementary and not of much interest in itself. Its only value lies in its possible truth. But if the thesis is true, then reading or writing the book would appear to be an entire waste of time, since it reinforces no behavior.

68

The passage suggests that Skinner’s position is that our A B C D

69

Skinner’s thesis, as it is presented in the passage, implies that A B C D

34

behavior is unpredictable. perception of free will is illusory. genetic endowments determine which reinforcers are most influential. behavior is irrevocably changed once we are aware of what influences our behavior.

no-one should be personally credited for any achievement. human behavior can never be fully understood or controlled. contentment is only possible when one is aware of one’s behavioral influences. failure is created by the individual whereas success is created by the environment.

5

10

15

20

25

70

When he writes ‘this escape is hardly available’ (lines 24 and 25), Chomsky’s tone is A B C D

71

In saying that ‘Its only value lies in its possible truth’ (lines 25 and 26), Chomsky suggests that Skinner’s thesis A B C D

72

deserves to be true despite its faults. only makes sense if it is taken to be true. must remain unproven if it is to preserve its appeal. adds nothing to our understanding of human nature if it is wrong.

In lines 16–22, Chomsky describes a situation in which A B C D

73

cautious. diplomatic. patronising. disappointed.

a behavior is brought about by an indiscernible reinforcer. the reinforcer required to bring about a behavior is the behavior itself. the reinforcer of a behavior is too weak to cause a repeat of that behavior. the deprivation required to bring about a behavior occurs after the behavior has happened.

In lines 23 and 24 Chomsky outlines a ‘counterargument’ to his own position. Which one of the following could form part of that counterargument? A B C D

Creativity can be an aversive reinforcer. Ideas can reinforce the act of seeking ideas for their own sake. Only behavior that is interesting and stimulating is worth reinforcing. Flawed notions can only reinforce positive behavior when people are aware of the flaws.

35

Questions 74 and 75

Questions 74 and 75 are from a debate for and against the topic that:

Nature is much more important than nurture.

For each of questions 74 and 75 you are to choose the alternative (A – D) that most appropriately describes the relationship of the statement to the topic of the debate.

The numbered statement: A B C D

is part of the debate for the topic. is part of the debate against the topic. could possibly be a part of the debate for or against the topic. is not a relevant part of either the debate for or against the topic.

74

Environment is the crucial determinant in development.

75

Twins raised in different environments have significant similarities.

36

37

Section II Written Communication Task A

Consider the following comments and develop a piece of writing in response to one or more of them. Your writing will be judged on the quality of your response to the theme, how well you organise and present your point of view, and how effectively you express yourself. ******* Comment 1 It does not take much to reveal the primitive and animal side of human nature.

**** Comment 2 Human nature is malleable. It can take all sorts of shapes.

**** Comment 3 Cooperation is the essential characteristic of human beings.

**** Comment 4 We cannot depend on the kindness and generosity of human beings.

38

Task B

Consider the following comments and develop a piece of writing in response to one or more of them. Your writing will be judged on the quality of your response to the theme, how well you organise and present your point of view, and how effectively you express yourself. ******* Comment 1 Fantasy is a way of understanding reality.

**** Comment 2 Fantasy is no more than escapism.

**** Comment 3 Imagination is one of the most important kinds of thinking.

**** Comment 4 Sympathy and empathy are dependent on imagination.

39

Section III Reasoning in Biological and Physical Sciences Questions 1 – 4 Figure 1 indicates blood flow through the heart. In a cardiac cycle, the period of ventricular contraction is ventricular systole and the period when ventricles are relaxed is ventricular diastole. During the normal cardiac cycle a stethoscope detects two sets of sounds. The first results from the virtually simultaneous snapping shut of the mitral and tricuspid valves and the second results from the not quite simultaneous snapping shut of the pulmonary valve and aortic valve.

aortic valve

S Q R

left atrium pulmonary valve

P

right atrium mitral valve

tricuspid valve

left ventricle right ventricle

apex Figure 1

1

Which of the four valves are open during ventricular systole? A B C D

2

Which vessels carry oxygenated blood? A B C D

40

mitral and tricuspid valves only aortic and pulmonary valves only both mitral and tricuspid valves and aortic and pulmonary valves neither mitral and tricuspid valves nor aortic and pulmonary valves

S and Q R and P P and Q Q and R

Questions 3 and 4 refer to the following additional information. Consider four conditions (Table 1) that lead to abnormal heart sounds, and the illustrative graphs labelled I to IV in Figure 2. The order of the conditions in the table does not necessarily correspond to the order of the graphs. In the graphs: •

The black rectangle represents the first sound in a cardiac cycle resulting from the shutting of the mitral valve and tricuspid valve.

•

The grey rectangle represents sounds related to the shutting of the pulmonary valve.

•

The striped rectangle represents sounds related to the shutting of the aortic valve.

•

Less pronounced sounds of lower pitch are represented by the thin vertical lines, with the height of the lines indicating the relative intensity of the sound – normally the aortic valve closes before the pulmonary valve and the sounds corresponding to the vertical lines are absent or minimal. Table 1 Condition

Description

aortic stenosis

aortic valve narrowed or obstructed so blood flow is restricted and turbulent

pulmonic stenosis

pulmonary valve narrowed or obstructed so blood flow is restricted and turbulent

aortic regurgitation

aortic valve does not fully close so blood can flow back through the valve

pulmonic regurgitation

pulmonary valve does not fully close so blood can flow back through the valve

Systole

Diastole

I

Intensity

II III IV

Normal Figure 2

3

Which of the following is most likely to represent aortic regurgitation? A B

4

I II

C D

III IV

The thin vertical lines during ventricular diastole correspond to A B C D

the degree of ventricular contraction. the degree of contraction of the atria. blood flowing from the ventricles into the atria. blood flowing from the arteries into the heart.

41

Questions 5 – 7 The four graphs below show the same vowel sound (fundamental and resulting resonances) when produced through the vocal tract under different conditions. The distance between two peaks of the same amplitude represents one pulse. The glottal pulse rate is the rate of opening and closing of the vocal folds.

fast glottal pulse rate

short vocal tract length

slow glottal pulse rate

long vocal tract length

12 ms

1 T

8 ms

•

f =

•

All the graphs are drawn to the same scale.

5

What is the frequency of the sound produced through the short vocal tract length? A B C D

6

the period of the sound is shorter. the resonance decays much more slowly. the resonance decays much more quickly. the frequency of the sound emitted is higher.

A longer vocal tract length and a faster glottal pulse rate result in a period A B C D

42

0.125 Hz 1.25 Hz 12.5 Hz 125 Hz

Compared with a long vocal tract length, for a short vocal tract length A B C D

7

where f is frequency (Hz) and T is period (s).

decrease and resonance lasts longer. increase and resonance lasts longer. decrease and resonance reduces more quickly. increase and resonance reduces more quickly.

Questions 8 – 10 Citric acid, C3H5O(COOH)3, is a tribasic acid. The three deprotonations, at 25 °C, can be represented as:

H3A

8

pKa2 = 4.28

HA2–

pKa3 = 5.21

A3–

C3H5O(COOH)3 C3H5O(COOH)2(COO−) C3H5O(COOH)(COO−)2 C3H5O(COO−)3

At what pH value are the concentrations of C3H5O(COOH)2(COO−) and C3H5O(COOH)(COO−)2 ions the same? A B C D

10

H2A–

What is the predominant species in a 0.10 M solution of citric acid at pH 5? A B C D

9

pKa1 = 2.92

pH 3.6 pH 4.1 pH 4.75 a pH value other than A or B or C

As temperature increases, the proportion of deprotonated species increases and therefore A B C D

pKa1, pKa2 and pKa3 will all increase. pKa1, pKa2 and pKa3 will all decrease. pKa2 will remain the same, but pKa1 and pKa3 will become closer to pKa2. pKa2 will remain the same, but pKa1 and pKa3 will become further from pKa2.

43

Questions 11 – 13 The figure below shows the major stages of the cell cycle for dividing cells. The stages of the cell cycle represent necessary steps in the process by which cells divide to yield two daughter cells. Most cells in the body at any time are in non-dividing phase G0, in which the cells have exited the G1 stage, though many cells can subsequently return to G1. During phase S, chromosomal replication takes place. cytokinesis

M

mitosis

intenance

G2

G1

DN

A

11

c ma

mitosis and cell division

ell

cell prepares to divide

C

int

S

syn

G0

er phase

thesis

In terms of the amount of time a dividing cell spends in each stage, the most variable stage of the cell cycle is likely to be A B C D

G1. S. G2. M.

Questions 12 and 13 refer to the following additional information. The amount of DNA in each cell of a population of cells can be measured using flow cytometry. A fluorescent dye that binds to DNA is used so that the relative level of fluorescence per cell is directly proportional to the amount of DNA. The graph gives flow cytometry results for a population of cells that is actively progressing through the cell cycle.

Number of cells

I

II 0

44

III

500 Rel. fluorescence (per cell)

1000

The height of peak I indicates that A B C D

Which of the following flow cytometry graphs would most likely be produced by a sample of living cells that is not actively dividing? C Number of cells

A Number of cells 0

500 Rel. fluorescence (per cell)

1000

B

0

500 Rel. fluorescence (per cell)

1000

0

500 Rel. fluorescence (per cell)

1000

D Number of cells

13

most of the cells in the sample are in G1. cells spend a very long time in the S phase. cells in G2 have twice as much DNA as those in G1. cells in G1 fluoresce more than those in any other phase of the cell cycle.

Number of cells

12

0

500 Rel. fluorescence (per cell)

1000

45

Questions 14 − 17 Paclitaxel is a drug that is used to treat tumours. It is a highly lipophilic drug and thus has low aqueous solubility. To improve the absorption of the drug, paclitaxel is usually delivered with polyoxyethylated castor oil and dehydrated ethanol, which help dissolve the drug. However, polyoxyethylated castor oil can cause severe side effects in patients, so an alternative is desirable. Another way of improving the absorption of the drug is to use a self-emulsifying drug delivery system (SEDDS). To find a suitable SEDDS, two or more components in a drug formulation are kept constant while the concentrations of three of the other components are varied. In the trials represented below, formulations each containing 5% vitamin E, 32% ethanol and 3% paclitaxel were used, and the remaining 60% of each formulation consisted of varying amounts of the surfactants sodium deoxycholate (DOC-Na, a bile salt), tyloxapol and d--tocopheryl polyethylene glycol 1000 succinate (TPGS). A pseudo-ternary phase diagram showing the relative amounts of DOC-Na, tyloxapol and TPGS for each formulation is shown below. In this diagram, Region X represents opaque macroemulsions (1 µm), Region Y nanosized emulsions (50–200 nm), and Region Z transparent microemulsions (1–10 nm). The most stable emulsions, which had no drug precipitation, occurred when DOC-Na was less than 50% and tyloxapol greater than 10%.

0%

60%

15%

Increasing DOC-Na

45%

4

30% 2

Z

30%

Increasing TPGS

3 45%

1

X

15%

Y 60% 0%

15%

30% Increasing tyloxapol

46

45%

0% 60%

14

The formulation represented at point 1contains A B C D

15

21% TPGS, 13% DOC-Na and 26% tyloxapol. 21% TPGS, 26% DOC-Na and 13% tyloxapol. 13% TPGS, 26% DOC-Na and 21% tyloxapol. 13% TPGS, 21% DOC-Na and 26% tyloxapol.

Formulation P contains 15% tyloxapol and formulation Q contains 30% tyloxapol. Which one of the following is true? A B C D

16

Formulations containing at least 40% DOC-Na can only be A B C D

17

P must be a microemulsion and Q must be a macroemulsion. P must be a macroemulsion and Q must be a microemulsion. Both P and Q could be microemulsions. Both P and Q could be macroemulsions.

microemulsions. macroemulsions. nanosized emulsions. microemulsions or macroemulsions.

Which of the following is closest to the maximum proportion of DOC-Na in the formulation that could form a microemulsion? A B C D

15% 30% 45% 60%

47

Questions 18 – 20 Helper T cells (Th cells), one of several types of T cell, are involved in the immune response to specific antigens*. Each Th cell has receptors for one of many possible specific antigens. A resting Th cell is activated when exposed to its complementary antigen. Once activated, it begins to secrete the growth factor IL-2 and to produce IL-2 receptors. IL-2 stimulates the division of Th cells to produce two identical daughter cells, which can themselves be activated by the same complementary antigen. Other types of T cell also produce IL-2 receptors in response to activation by antigen. The figure shows IL-2 molecules interacting with the IL-2 receptors on an activated Th cell. *  antigen: any substance that stimulates the immune system to produce an immune response such as antibodies (proteins that bind to antigens).

Th cell IL-2 receptor

IL-2 molecule

18

Which of the following is likely to best represent the initial proliferation of Th cells in response to their complementary antigen? A

C Number of Th cells

Number of Th cells Time

B

D Number of Th cells

Number of Th cells Time

48

Time

Time

19

Which of the following best explains the value of the process described? The process allows a rapid increase in the number of A B C D

20

IL-2 molecules. Th cells. IL-2 receptors on Th cells. Th cells complementary to a specific antigen.

Which of the following would most likely inhibit the division of Th cells? A B C D

inducing resting Th cells to express IL-2 receptors prior to activation by antigen injecting excess IL-2 injecting excess unattached IL-2 receptors increasing the number of IL-2 receptors on Th cells

Question 21 The most common domestic voltages used around the world are 240 V and 110 V. In general, the risk to a person who makes contact with an electrical source is directly proportional to the size of the current. The table gives the typical electrical resistances of the human body for two different contact voltages.

21

Voltage (V)

Resistance (Ω)

110

3000

240

2200

Assuming all other factors are equal, which of the following is the closest estimate of the ratio of the risk to a person from a 240 V source compared to a 110 V source? A B C D

2 : 3 2 : 1 3 : 1 4 : 3

49

Questions 22 – 24 The retrocyclisation of cyclobutenes to form butadienes can be promoted either thermally (T), resulting in both end groups rotating clockwise or both anticlockwise, or photochemically (λν), resulting in one end group rotating clockwise and the other anticlockwise. Rotational direction of attached groups is referred to as in or out:

Δ out

R1

R2 in

R3 in

R1

R4

R4 R2

out

R3

The preference for in or out is influenced by the nature of the attached atoms (–R). The table shows estimated differences in activation energy for the rotations (Ein – Eout).

–R

–OCH3

–Cl

–CH3

–H

–CF3

–CN

–NO2

–CHO

Ein – Eout

14

10

7

0

–1

–2

–4

–5

The carbon for which the magnitude of the sum of Ein – Eout values is higher rotates in its preferred direction. Positive Ein – Eout values indicate a preference for in rotation. Negative Ein – Eout values indicate a preference for out rotation. •

Assume only the dominant product is formed.

22

Consider retrocyclisation of a cyclobutene for which R1 to R4 are some arrangement of H, H, Cl and CN. The chlorine atom will A B C D

50

always rotate in. always rotate out. rotate in or out, depending on the arrangement of H, H, Cl and CN. rotate in or out, depending on whether the reaction is thermally or photochemically promoted.

23

What arrangement of H, CF3 and Cl is produced by the photochemically promoted retrocyclisation of the cyclobutene at right?

A

F3C Cl

B

C

Cl

H

H Cl Cl

D

Cl

Cl

H CF3 Cl

CF3 H

24

Cl Cl

F3C

H

Cl

F3C

For the following structure, consider the set of molecules for which R is –OCH3, –Cl, –CH3, –CF3, –NO2 and –CHO.

NC

R

For how many of these molecules does the photochemically promoted reaction result in the R-group rotating in? A B C D

one two three four

51

Questions 25 – 27 During very early development of mammalian females, one of the two X-chromosomes normally present in each somatic cell becomes deactivated. Deactivation is random, with maternal and paternal X-chromosomes equally likely to be deactivated. All cells deriving from this cell carry the same deactivated X-chromosome, creating local patches of tissue with either maternal or paternal features. Anhidrotic ectodermal dysplasia (AED) is an inherited skin condition caused by the recessive allele (s) of a gene that has its locus on the X-chromosome. In some individuals with this condition, sweat gland distribution is patchy, with some areas lacking glands. In other individuals with this condition, all sweat glands are absent.

25

Which one of the following is consistent with the information given? A B C D

26

Which one of the following statements is not consistent with the information given? A B C D

27

Females with AED can have the genotype ss. Males with AED cannot carry the dominant allele, S. With respect to AED, males can have the genotype Ss. With respect to AED, females can have the genotype Ss.

In which of the following is AED most likely to be characterised by a total absence of sweat glands? A B C D

52

Patchy sweat gland distribution is found in males and females but is more likely in males with the condition. Patchy sweat gland distribution is equally likely in both males and females with the condition. Only females with the condition exhibit patchy sweat gland distribution. Only males with the condition exhibit patchy sweat gland distribution.

males inheriting an X-chromosome with the dominant allele from the mother males inheriting an X-chromosome with the recessive allele from the mother females inheriting an X-chromosome with the recessive allele from the father females inheriting an X-chromosome with the recessive allele from the mother

Questions 28 − 30 Positron emission tomography (PET) is used in many major hospitals as a diagnostic tool. Positrons are similar 0 to electrons but have a charge of +1 and so their symbol is 1 e . A radioactive isotope of fluorine, fluorine-18, is commonly used as the positron emitter. This isotope is produced in a cyclotron by bombarding oxygen-18 with protons.

28

29

Which one of the following nuclear equations represents the emission of positrons from fluorine-18? A

18 9F

18 8O

+

0 1e

B

18 9F

18 9F

+

0 1e

C

18 9F

18 Ne 10

+

0 1e

D

18 9F

17 Ne 10

+

0 1e

Radiation doses are calculated by the energy deposited per kilogram of body tissue, for which the SI unit is the gray (Gy). 1 Gy = 1 J kg−1 The average energy from a single annihilation is approximately 10−13 J and there is an average of 109 annihilations per second over the period of 20 minutes needed for a PET scan. What is the best estimate of the whole-body dose received by a 60 kg person during a PET scan? A B C D

30

2.0 Gy 0.20 Gy 0.020 Gy 0.0020 Gy

Which one of the following nuclear equations represents the production of radioactive fluorine in a cyclotron? A

18 O 8

+

1 1

H

18 9F

+

0 1e

B

18 O 8

+

1 1

H

18 9F

+

_1e

C

18 8O

+

1 1

H

18 9F

+

1 1H

D

18 8O

+

1 1

H

18 9F

+

1 0n

0

53

Questions 31 – 34 The circulatory system of a foetal mammal differs from that of the adult. Figure 1 shows the adult mammalian heart. Figure 2 represents a model of the foetal circulation of the lamb. On Figure 2 are two types of number: each bold number indicates the percentage of the combined output of the two ventricles, CVO (combined ventricular output), passing through that point; each italic number indicates the oxygen saturation (%) of the blood at that point. Some values are missing.

from body

to lungs

from lungs to body

aorta

from lungs

LA RA

Of the parts of the circulatory system numbered I–V in Figure 2, two are shunts that enable some of the blood to bypass part of the foetal circulatory system. These shunts close at birth.

LV RV from body

Where blood enters a chamber or vessel from multiple sources, it may mix fully, partially, or not at all, depending on the degree to which the incoming streams are separated.

Figure 1

The foetal lungs are non-functional, although blood still passes through them. Gas exchange occurs in the placenta. •

Answer all questions according to this model.

•

The following formula may be useful, in which c is concentration, V is volume: cfinal =

? SVC 25

c1V1 + c2V2 V1 + V2

tissues 46 67

I

IV

LV

LA

58 62

III 12 ?

RA RV

42 52

lungs V

30 52

IVC

SV

? 27

tissues

SA

? ?

UV

? 80

placenta

UA

? ?

Figure 2

aorta 73 ?

? 67

II

54

SVC IVC SV SA UV UA RA RV LA LV

? ?

superior vena cava inferior vena cava systemic veins systemic arteries umbilical vein umbilical artery right atrium right ventricle left atrium left ventricle

31

Which of I–V are the shunts that normally close at birth? A B C D

32

Blood flow A B C D

33

into the RA is equal to blood flow out of the LV. into the RA is greater than blood flow out of the LV. through the IVC is equal to blood flow through the SVC. through the IVC is less than blood flow through the SVC.

Which of the following best estimates the oxygen saturation in the SA? A B C D

34

I and IV I and V II and IV II and V

70% 64% 58% 52%

What percentage of CVO flows through IV? A B C D

12% 15% 43% This percentage cannot be determined from the information provided.

55

Questions 35 and 36 The diagram below summarises the key energy transfer steps during the oxidation of glucose and ethanol.

NAD+

NADH

O

OH

H ethanal

ethanol O

HO

OH

NAD+

OH OH

½ glucose

NAD+

O

NADH

O

3 ADP + 3P ½ O2

NADH

H2O

NAD+

3 ATP

O CO2

O

2 ADP 2 ATP + 2P

ADP +P

56

NADH

OH HO

•

NADH

NAD+

acetate

pyruvate O

OH

O

citrate

O

O 3 NADH

O O

oxaloacetate

Answer the following questions according to only the information provided.

CoA

acetyl-CoA

O O

3 NAD +

O

O

O

2 CO2 + ATP

O

O

35

Which of glucose, oxaloacetate and NADH, if labelled with 13C-labelled ATP? A B C D

36

13C,

would result in the production of

glucose oxaloacetate NADH none of glucose, oxaloacetate or NADH

How many moles of ethanol are needed to produce as much ATP as would be produced by one mole of glucose? A B C D

less than one more than one, but less than two more than two, but less than four more than four

57

Questions 37 – 39 A lens is a piece of transparent material that is generally curved on both surfaces. If the thickness of the lens is small compared with its focal length (the distance at which it focuses light) then the thin lens formula can be used to determine the overall focal length of the lens. The thin lens formula is: 1 1 1 = (n −1) ( − − ) R1 R2 f where

f is the focal length of the lens n is the refractive index of the material used to make the lens R1 is the radius of curvature of the surface nearest to the light source R2 is the radius of curvature of the surface furthest from the light source.

The sign convention for focal length is that f is positive for a converging lens (parallel rays of light enter the lens and are focused to a point on the other side) and negative for a diverging lens (parallel rays of light enter the lens and spread out, appearing to come from a point). The sign convention for the radii of curvature is as follows:

37

Concave surface

R1

positive

negative

R2

negative

positive

The focal length of a biconvex lens that has curvature radii of 60 cm on both sides and is made of a material with a refractive index of 1.75 is A B

38

Convex surface

20 cm. 40 cm.

C D

50 cm. 67 cm.

Consider a biconvex lens for which the radius of curvature of one side is quite different to the radius of curvature of the other side. What would be the effect of reversing this lens? A B C D

39

Its focal length would be the inverse of the original focal length. If the lens was originally a converging lens, it would now be a diverging lens. There would be no change; the lens would refract light in the same way. The values of n, R1 and R2 need to be known in order to determine if there is a change.

Consider a symmetrical biconvex lens that has a focal length as long as its radius of curvature. What is the refractive index of the material used to make this lens? A B

58

1.33 1.50

C D

1.75 2.00

Questions 40 – 42 A car can be fitted with a breath alcohol interlock ignition device (BAIID), which is designed to prevent a driver with a blood alcohol content greater than 0.05% from starting the car. Before the car can be started, the driver must blow into the BAIID. This contains an electrochemical device that oxidises alcohols in the breath, thus producing a current. The amount of current produced is a direct measure of the blood alcohol content. Typically, the alcohol that is tested for is ethanol but the device is able to oxidise all volatile alcohols. Fred has not consumed any alcohol (ethanol) in the past week and is on a very low calorie diet (VLCD) to lose weight. Such diets provide adequate amounts of protein and fat but little carbohydrate. After only a few days on these diets, fat is metabolised, leading to high concentrations of propanone, -hydroxybutyrate and acetoacetate (3-oxo-butanoate) in the blood. Propanone is a volatile ketone that is removed from the body by being exhaled and excreted in urine. Its half-life in the body is about 20 hours, and it can be reduced to form 2-propanol, with a half-life of about 4 hours. •

The half-life in this context is the time taken to remove half of the compound from the body.

40

If Fred tries to start a car fitted with a BAIID, the car A B C D

41

would start because Fred has not consumed any alcohol. would start because the half-life of 2-propanol is less than that of propanone. may not start due to the 2-propanol content in his breath. may not start due to the propanone content in his breath.

Suppose 2-propanol is detected in Fred’s breath. Which of ethanol or propanone is also likely to occur in Fred’s breath? A B C D

42

ethanol but not propanone propanone but not ethanol both ethanol and propanone neither ethanol nor propanone

Which one of the following would be detected in Fred’s breath by a BAIID if Fred maintains his diet? A B C D

ethanol propanone 2-propanol 3-oxo-butanoate

59

Questions 43 – 46 When mammals and birds inhale, the inhaled air rapidly equilibrates to body temperature and becomes saturated* as water vapour is added by evaporation from the surfaces of the respiratory tract. During exhalation, the air exiting the body remains saturated but is usually cooled as it passes out through the nasal passages (by either heat exchange with vascular counter-current structures within the nasal passages, or, at least in some birds, with the uninsulated bill and surrounding area). Such cooling causes water vapour to condense from the air onto the surfaces of the nasal passages, and thus the body recovers some of the water added to the air upon inhalation. The figure indicates, for different temperatures, the amount of water vapour in air with a relative humidity of 25% or 100%. * Saturation equates to a relative humidity of 100%. (Relative humidity is the amount of water vapour that exists in air, expressed as a percentage of the maximum possible. The maximum possible is dependent on temperature.)

60

Water in air (mg L–1)

50 40

relative humidity 100% 25%

30 20 10 0

43

0

10

30 20 Air temperature (°C)

40

Consider a human with a body temperature of 37 °C inhaling air of 25 °C with 25% relative humidity. Which of the following is closest to the mass of water added to each litre of air as it becomes saturated and equilibrates to body temperature? A B C D

60

20 mg 25 mg 40 mg 45 mg

44

Which one of the following statements is correct? A B C D

45

As the temperature of ambient air increases, its humidity has less effect on the amount of water lost in exhaled air. As the temperature of ambient air increases, its humidity has less effect on the amount of water added to inhaled air. Less cooling of the air passing through the nasal passages during exhalation results in more water being recovered. More cooling of the air passing through the nasal passages during exhalation results in more water being recovered.

Consider a kangaroo rat inhaling air of 30 °C with 25% relative humidity, and exhaling saturated air of 27 °C. Which of the following is closest to the net loss of water from the kangaroo rat for every litre of exhaled air? A B C D

46

20 mg 28 mg 36 mg 40 mg

Which one of the following would not improve heat exchange in the nasal passages? A B C D

short nasal passages narrow nasal passages nasal passages with highly folded surfaces nasal passages with counter-current blood flow

61

Questions 47 – 49 For some carboxylic acids of general formula R–COOH, the table shows the formulation of the R-group and the value of property H. R–

H

H–

57.4

CH3–

67.7

ClCH2–

45.6

CH3CH2–

68.8

2-chloropropanoic acid

ClCH2CH2–

45.2

3-chloropropanoic acid

ClCH2CH2–

60.0

n-butanoic acid

CH3CH2CH2–

68.3

2-chlorobutanoic acid

CH3CH2CHCl–

45.6

3-chlorobutanoic acid

CH3CHClCH2–

60.7

4-chlorobutanoic acid

ClCH2CH2CH2–

65.5

Systematic name methanoic acid ethanoic acid chloroethanoic acid propanoic acid

47

Which of the following is the best estimate of the value of H for 2-chloropentanoic acid? A B C D

48

Which of the following is most likely to have a value of H closest to 60.7? A B C D

49

46.1 57.7 61.1 68.4

3-chloropentanoic acid 4-chloropentanoic acid 4-chlorohexanoic acid 5-chlorohexanoic acid

Which of the following is most likely? The value of H of A B C D

62

3-chloro-2-methylbutanoic acid is less than that of 2-chloro-3-methylbutanoic acid. 3-chloro-2-methylbutanoic acid is less than that of 4-chloro-3-methylbutanoic acid. 4-chloro-2-methylbutanoic acid is less than that of 2-chloro-3-methylbutanoic acid. 5-chloropentanoic acid is less than that of 3-chloro-3-methylbutanoic acid.

Questions 50 and 51 As the number of hours of daylight each day decreases with the approach of winter, insects stop their growth and development. This stopping of insect growth and development is called diapause. How do insects measure the number of hours of daylight per day? Research into this question has often involved artificially varying the durations of light and darkness each 24 hours, and measuring the resulting proportion of the insect population entering diapause. The figure shows the percentage of S. argyrostoma flies that are in diapause when the number of hours of (artificial) daylight in each 24-hour day is varied. (The flies cannot distinguish artificial daylight from real daylight.) Flies that are not in diapause grow and develop. 100

Percentage of flies in diapause

80 60 40 20 0 0

2

4

6

8

10

12

14

16

18

20

22

24

Hours of light per 24-hour day

50

51

Eighty per cent of the fly population grows and develops when the number of hours of light per day is somewhere between A

4 and 5 hours only.

B

13 and 14 hours only.

C

14 −2 and 15 −2 hours only.

D

both 4 and 5 hours, and 13 and 14 hours.

1

1

For which of the following does the largest percentage of the fly population grow and develop? A B C D

0 hours of light per day 6 hours of light per day 10 hours of light per day 14 hours of light per day

63

Question 52

52

Two six-base fragments obtained from a single 12-base DNA sequence are ATTGAT and ATATTG. The two fragments represent at least A

8 − 12

of the sequence.

B

9 − 12

of the sequence.

C

10 − 12

of the sequence.

D

11 − 12

of the sequence.

Question 53 The diagram below shows the partitioning of a particular compound in equal volumes of three mutually immiscible solvents. I

40

?:?

15:

II

?:?

III

The total amount of the compound dissolved in this system is 2.3 mol. The amount of the compound dissolved in solvent II is 1.2 mol.

53

Which of the following is closest to the ratio of the concentrations of the solutions (I:II:III)? A B C D

64

3:12:8 3:8:12 12:3:2 9:6:16

Questions 54 − 56 Normal eye colour in a particular species is maroon – the result of the presence of two pigments, brown and red. The development of the brown pigment is controlled by the gene brown; the development of the red pigment is controlled by the gene red. •

Both brown (Bw and bw) and red (Rd and rd) occur as a single pair of dominant–recessive alleles.

•

For both brown and red, no pigment is expressed in the homozygous recessive phenotype.

•

Individuals that are homozygous recessive at both pigment loci have white eyes.

•

Both brown and red are found on chromosome II, an autosome.

Figure 1a represents a trans-dihybrid genotype (i.e. with the recessive allele of each gene located on different homologs) and Figure 1b represents a dihomozygous recessive genotype. Note that crossing-over does not occur in males of this species, so any alleles present on a chromosome are always transmitted together (i.e. without recombination with alleles on the homologous chromosome). Crossing-over in females occurs as normal. •

Assume that brown and red are the only genes affecting eye colour. maroon eyes Rd bw



54

rd Bw

white eyes rd bw

rd bw

Figure 1a

Figure 1b

Dihomozygous red-eyed males are crossed with cis-dihybrid females. In females, there is 50% recombination between the brown and red loci. What are the expected eye-colour proportions of the progeny? A B C D

55

If a trans-dihybrid male is crossed with a white-eyed female, what eye colours can the progeny have? A B

56

all red-eyed all maroon-eyed red-eyed and brown-eyed in equal proportions maroon-eyed and red-eyed in equal proportions

maroon, red, brown and white maroon, red and brown only

C D

red and brown only red and white only

Brown-eyed phenotypes A B C D

must be homozygous for the rd allele. must be homozygous for the bw allele. can be either homozygous or heterozygous for brown. can be either homozygous or heterozygous for red.

65

Questions 57 – 60 A person jumps by first crouching, thus lowering their centre of mass by a distance, c, and then pushing downwards with constant force, F, to extend their legs. The jump raises their centre of mass from its original position by a distance, j.

j c

Assume that the force needed for a person to raise their centre of mass by j is k times their weight: F = kmg where

m is mass g is acceleration due to local gravity.

The force of gravity on the surface of the Moon is one-sixth as strong as on the surface of Earth. It can be shown that, for the same magnitude F, jEarth = c(kEarth – 1)

and

jMoon = c(kMoon – 1) = c(6kEarth – 1).

•

Assume that m and c are the same for all jumps.

57

Consider jumps on Earth and the Moon. A person will only leave the ground

58

A

on Earth if kEarth = 1 and on the Moon if kMoon = 1.

B

on Earth if kEarth > 1 and on the Moon if kMoon > 1.

C

on Earth if kEarth = 1 but on the Moon only if kMoon = 6.

D

on Earth if kEarth > 1 but on the Moon only if kMoon > 6.

Suppose that a person jumps 11 times as high on the Moon as on Earth when using equal force. How large is the force exerted by the person jumping? A B C D

66

the same as the person’s weight on Earth the same as the person’s weight on the Moon twice the person’s weight on Earth twice the person’s weight on the Moon

59

Consider a person who jumps on the Moon using a force that is six times their weight on the Moon. If the person uses equal force on Earth, they will A B C D

60

not leave the ground. jump as high as on the Moon. jump one-sixth as high as on the Moon. jump five-sixths as high as on the Moon.

Consider a planet with one-third the gravity of the Earth. For jumps using equal force on the other planet and on Earth, which of the following is correct? A

jMoon

jPlanet

>

jMoon jEarth

B

jMoon jMoon < jPlanet jEarth

C

jMoon 1 jMoon = jPlanet 3 jEarth

D

jMoon =2 jPlanet

67

Questions 61 – 63 Digitalis, which contains digitoxin, increases the speed and force of heart contraction. It is therefore a very useful treatment for people with certain heart diseases. Digitalis is extracted from the foxglove plant. Unfortunately, digitalis extracts can produce side effects such as vomiting. William Withering, an English physician, pioneered the use of digitalis on a routine basis in the second half of the eighteenth century. The figure below indicates the results he obtained using four different methods of preparing digitalis from foxglove plants. For each preparation method: •

the left-hand bar indicates the number of patients with side effects

•

the centre bar indicates the total number of patients

•

the right-hand bar indicates the number of patients who were treated successfully.

80 70

Number of patients

60 50 40 30 20 10 0

68

unspecified method

alcoholic dried extract leaf Preparation

watery extract

61

According to the data provided, an advantage of the dried leaf preparation over the watery extract is that A B C D

62

the percentage of patients with side effects was about a third. the percentage of patients treated successfully was greater. fewer patients were needed to show that it was a successful treatment. fewer patients were needed to show that it had side effects.

For the watery extract, suppose that side effects only occurred for patients who were treated successfully. How many patients had neither a successful treatment nor a side effect? A B C D

63

17 25 36 52

For the alcoholic extract, suppose that the greatest possible number of patients who were treated successfully had side effects. The number with side effects who were not treated successfully is A B C D

zero. three. four. seven.

69

Questions 64 and 65 Dental cements, which are used to fill cavities in teeth, are made by mixing a metal oxide powder with an acidic liquid. The metal oxide contains divalent ions, such as Ca2+, Mg2+ and Zn2+, or trivalent ions, such as Al3+. The acidic liquid contains divalent anions, A2−, or trivalent anions, A3−. For example, metal ions, M2+, and divalent anions, A2−, form a dental cement of the form MA, as shown. MO

+

powder

H2A

MA

acidic liquid

dental cement

+

H2O

The figure shows the percentage by mass of evaporable and non-evaporable water in four dental cements at various times after mixing, and the compressive strength of the cements at these times. The hydration of a dental cement is the ratio of non-evaporable water to evaporable water. evaporable

zinc polycarboxylate

non-evaporable

20 zinc phosphate

silicate glass ionomer

% m/m

15

10

5

0

Time (h)

0

Compressive – strength (MPa)

64

4

0

0.5

4

340

0

0.5

340

0

0.5

–

40

62

75

–

71 146 275

4

–

117 201 252

M2A3 M3A2 M3A MA2

Which one of the following is true based on the information given? A B C D

70

340

93 141 150

4

340

Which one of the following represents the formula for a dental cement formed by reacting a trivalent metal ion with a divalent anion? A B C D

65

0.5

The weakest cement is the most hydrated. The hydration of cements increases with age. Zinc cements are more hydrated than glass ionomers. As hydration increases, the compressive strength of the cement decreases.

Question 66 Each strand of DNA has a negatively charged phosphodiester-deoxyribose backbone, as shown in the figure on the left. PNA (peptide nucleic acid) has an uncharged backbone of repeating N-(2-aminoethyl)-glycine molecules linked by peptide bonds. It is able to form base pairs with complementary DNA strands, as shown in the figure on the right.

OH

OH A

O O O

O O

OH O—

P

O O

O P

G

O

O—

OH 66

T

O

DNA

O

O O P O— O

A

O

O O P O— O

N O

O O — O P O O C

O

T

A

NH 2

O O P O— O

G

C

O O O— O O

DNA

P

O

T

OH

N

PNA O

O O — O P O O

O C

G

NH

NH

T

N

O

DNA

O

O — O P O O

O

N O

G

C

NH

A

O

OH

CONH 2

Compared to a fragment of double-stranded DNA, the analogous fragment of double-stranded PNA will have A B C D

a higher solubility in water. the same solubility in water. a lower solubility in water. a higher or lower solubility in water, depending on the base sequence.

71

Questions 67 and 68 Many birds are able to soar (fly without flapping their wings) by circling in the air. The air provides a lifting force on the outstretched wings of a soaring bird. The lifting force partly opposes the bird’s weight and helps to keep it in the air. For a soaring bird, the figure shows the relationships between its speed, the time it takes to complete one full circle of a horizontal circular path, the radius of its circular path, and its angle of bank. The angle of bank is the angle between the line joining the tips of the outstretched wings of the bird and the horizontal plane containing the bird’s path. When the bird banks, the lift acting on its wings is tilted from the vertical by the angle of bank. The lift has horizontal and vertical components, but only the vertical component of the lift is available to counter the bird’s weight. For example, as shown in the figure, if the speed is 4 m s–1 and the time for one complete circle is 11 s, the circular path of a soaring bird has a radius of approximately 7 m and an angle of bank of approximately 13°.

Angle of bank 50 20

15 14

24

40

35

28

32

30 36

40

45

25

16 14

(m)

13

pat h

12

12 20

10

ircu

lar

11

of c

10

ius

9 8

Rad

Speed (m s–1 )

45

7

8 15

6

4

6

10

5

2

4 3

5

2 1 0

0

1

2

3

4

5

6

7

8

9

10

11 12

13 14

Time for full circles (s)

72

15 16

17 18

19

20

67

A bird of mass 2 kg is soaring in a circular path. The speed of the bird is 12 m s–1 and its angle of bank is 25°. If the bird halves the radius of its circular path and increases its angle of bank by 10°, which of the following is the best estimate of the bird’s speed in its new path? A B C D

68

  2 m s–1   4 m s–1   8 m s–1 10 m s–1

A bird of mass 2.5 kg is soaring in a circular path with a radius of 10 m. The magnitude of the centripetal force acting on it is equal to the magnitude of its weight. Centripetal force can be calculated from the following formula. F =

mv2 r

Which of the following is the best estimate of the angle of bank at which the bird is soaring? A B C D

30° 35° 40° 45°

73

Questions 69 – 72 The enzyme alcohol dehydrogenase (ADH) oxidises alcohols. The enzyme effectively removes the hydrogen atom of the alcohol (-OH) group and a hydrogen atom on the carbon to which this alcohol group is attached. The reaction also requires the presence of the coenzyme nicotinamide adenine dinucleotide (NAD), as described in the following reaction scheme. H C

O

H

ADH NAD

H C = O

H

69

Consider these four alcohols: 1,1-dimethylethanol (CH3C(CH3)2OH), n-hexanol (C6H13OH), cyclohexanol (C6H11OH) and benzylalcohol (C6H5CH2OH). In the presence of the coenzyme NAD, the only one of these alcohols that ADH will not react with is A B C D

70

The reaction of 2-pentanol catalysed by ADH in the presence of NAD would produce A B C D

71

1,1-dimethylethanol. n-hexanol. cyclohexanol. benzylalcohol.

pentanal (pentylaldehyde). 2-pentanone (methylpropylketone). 3-pentanone (diethylketone). 2-pentanoic acid.

Illegally brewed spirits often contain wood alcohol (methanol) as well as ethanol. Consider the following statements about the reactions catalysed by ADH in the presence of NAD with these two alcohols. I

Methanol is metabolised by ADH to form formaldehyde (HCHO).

II

Ethanol is metabolised by ADH to form acetaldehyde (CH3CHO).

Which one of the following is true? A B C D

72

Which one of the following statements about the reactions of alcohols catalysed by ADH in the presence of NAD is correct? A B C D

74

Statement I is correct but statement II is incorrect. Statement II is correct but statement I is incorrect. Both statements I and II are incorrect. Both statements I and II are correct.

The product formed by the reaction of a primary alcohol is a ketone. The product formed by the reaction of a secondary alcohol is an aldehyde. The product formed by the reaction of a tertiary alcohol can be either an aldehyde or a ketone. ADH does not catalyse reactions of tertiary alcohols.

Questions 73 – 75 Figure 1 gives oxyhaemoglobin dissociation curves (i.e. Hb saturation with O2 vs Po2) for typical birds of two species, X and Y. Figure 2 gives percentage increase in ventilation volume for the two birds in response to certain levels of induced hypoxia. •

Hb saturation is the %Hb that is in the form of HbO2.

•

All measurements were done at standard pH and temperature.

100 90

X

% Hb saturation

80

Y

70 60 50 40 30 20 10

Percentage increase in ventilation volume

X 200 175

125 100 75 50 25 10 20 30 40 50 60 70 80 90 100 PO2 (torr)

10 20 30 40 50 60 70 80 90 100 PO2 (torr)

73

Figure 1

Figure 2

Which of the following statements is most accurate? A B C D

74

Y

150

At a Po2 of 60 torr both birds have an increased ventilation volume. At a Po2 of 60 torr neither bird has an increased ventilation volume. The bird with the lower oxygen affinity increases ventilation at a lower Po2. The bird with the lower oxygen affinity increases ventilation at a higher Po2.

Which of the following statements is best supported? In Figure 2, the difference in starting Po2 (i.e. no increase in ventilation) is primarily related to the points on the two curves in Figure 1 where A B C D

75

HbO2 = 50%. Po2 = 50 torr. the curves begin to flatten towards the top. the curves begin to flatten towards the bottom.

Which of the following is closest to the difference between Hb saturation of the two birds when increased ventilation starts to occur? A B

5% 10%

C D

20% 30%

75

Questions 76 − 78 Monosaccharides have names that end with -ose and can be classified by the number of carbon atoms they contain. For example, a monosaccharide with three carbon atoms is called a triose, with four carbons a tetrose, with five a pentose and with six a hexose. The prefix aldo- indicates that the monosaccharide contains an aldehyde group (-CHO), and the prefix keto- indicates that it contains a ketone group (>C=O). Two examples are shown below. HO

CH2 CH

CH

OH

OH

CH=O

HO

CH2 CH OH

an aldotetrose

CH

CH

C

OH OH

O

CH2 OH

a ketohexose

A carbon atom with four different groups attached to it is called a stereocentre. Molecules containing stereocentres exist as stereoisomers.

76

Consider the structure of the following molecule. H

C CH

CH

CH

O OH OH

OH

CH2 OH

Which of the following best describes this monosaccharide? A B C D

77

It is an aldopentose with three stereocentres. It is an aldopentose with four stereocentres. It is a ketopentose with three stereocentres. It is a ketopentose with four stereocentres.

Consider two monosaccharides with the same number of carbon atoms. One contains an aldehyde group while the other contains a ketone group. Which of the following best describes these monosaccharides? A B C D

78

The aldose will have the same number of stereocentres as the ketose. The aldose will have one more stereocentre than the ketose. The aldose will have two more stereocentres than the ketose. The difference in the number of stereocentres depends on the particular aldose and ketose.

Consider the number of carbon atoms in an aldose and a ketose and the number of stereocentres in each. The number of stereocentres in the A B C D

76

aldose will be one fewer than the number of carbon atoms. aldose will be three fewer than the number of carbon atoms. ketose will be two fewer than the number of carbon atoms. ketose will be three fewer than the number of carbon atoms.

Questions 79 and 80 The resistance of pathogenic micro-organisms to anti-microbial drugs is common. Sometimes resistance is quick to evolve and sometimes it evolves only after decades of drug use. Models are being developed to explain the different patterns of resistance evolution. These models assume that the patterns depend primarily on factors such as: I

the duration of the contagious period of infected individuals

II

the prevalence of drug treatment

III the degree to which treatment reduces the transmission of the infection IV the degree to which development of resistance reduces the competitive fitness of the pathogen V

the probability that a drug-sensitive micro-organism becomes resistant when treated.

79

With all other factors held constant, in which of the following situations is contagiousness most likely to lead to resistance? A B C D

80

I is long, IV is high. I is long, IV is low. I is short, IV is high. I is short, IV is low.

For genital herpes there is a long contagious period, reduced fitness of the virus after it becomes drug resistant and a low probability that treatment will lead to resistance. For influenza A there is a short contagious period, no reduction in fitness of the virus after it becomes drug resistant and a high probability that drug resistance will develop. Compared with influenza A, genital herpes is most likely to evolve resistance A B C D

more quickly because of both I and IV. more quickly because of both IV and V. more slowly because of both I and IV. more slowly because of both IV and V.

77

Questions 81 – 84 Although most organic compounds appear white or colourless, some are coloured because they have groups that absorb some visible radiation. These groups usually contain aromatic rings or conjugated double bonds. Multiple bonds separated by single bonds are said to be conjugated. The multiple bonds may be double or triple bonds, and may be between two carbon atoms or between a carbon and an oxygen or nitrogen atom. Examples of conjugated systems are CH2=CH–CH=CH2, CH2=CH–CHO and CH≡C–CH=CH–CN. The greater the number of such groups in a molecule, the longer the wavelength of the light that is absorbed.

81

A typical absorption spectrum is shown in the figure below. The wavelength of the peak of maximum absorption, denoted as λmax, occurs at 418 nm for this compound. 1.0

Absorbance

0.8 0.6 0.4 0.2 0.0 300

350

400

450

500 550 600 Wavelength (nm)

650

700

750

The proportion of the light absorbed depends on the nature of the compound, its concentration and the path length of the cell containing the solution and through which the light has passed. The molar absorptivity, ε, of the compound can be calculated from the equation

ε=

where



A cl

A is the proportion of the light absorbed c is the concentration of the solution (mol L–1) l is the path length (cm) of the cell containing the solution.

What would be the molar absorptivity of a compound if, at the wavelength at which the maximum absorption occurs, 90% of the light passing through a cell of width 2.0 cm containing a 0.050 M solution of this compound is absorbed?

78

A

0.9 L mol–1 cm–1

B

9 L mol–1 cm–1

C

90 L mol–1 cm–1

D

900 L mol–1 cm–1

82

Many synthetic dyes are based on azobenzene: N

N

Which one of the following groups, if attached to the benzene groups, would not increase the wavelength at which the maximum absorption occurs? A B C D

83

a carboxylic acid group a nitrile group an alkyl group an aryl group

The structure of β-carotene is shown below.

The reason that β-carotene is orange is that the molecule has A B C D

84

two six-membered rings that absorb at the red end of the visible spectrum. two six-membered rings that absorb at the blue end of the visible spectrum. a set of eleven conjugated bonds that absorb at the blue end of the visible spectrum. a set of eleven conjugated bonds that absorb at the red end of the visible spectrum.

Phenolphthalein is an acid–base indicator. It has different structures at different pH values, represented as structures I and II below, and so its colour, either colourless or pink, depends on the pH of the solution it is in.

OH

O

O−

OH

COO−

O O I

II

Which one of the following statements is correct? A B C D

I is the structure at low pH and is colourless. I is the structure at high pH and is colourless. II is the structure at low pH and is colourless. II is the structure at high pH and is colourless.

79

Questions 85 and 86 The figure summarises some data about the age-specific mortality rate of elderly people in the US. The mortality rate is given as the annual number of deaths of people in the age group divided by the number of people in the age group. Each age group spans a year, so the groups are 80-year-olds, 81-year-olds, and so on. According to the Gompertz law, the chance of an animal dying during adulthood rises exponentially with age. For example, the chance of an adult human dying in a particular year would double roughly every eight years. The expected line on the graph is based on an application of the Gompertz law after age 95.

1.0

Mortality rate

expected 0.5 observed

0

80

90

100

110

Age (years)

85

Suppose the Gompertz law applied to the data in the figure from age 80 (when the mortality rate is 0.1), with the probability of a human dying in a particular year doubling every five years. Which of the following is closest to the probability of a 95-year-old person dying before the age of 96? A B C D

86

Which of the following best helps explain why the observations differ from expected in the figure? A B C D

80

0.8 0.4 0.2 0.05

Older people are frailer than expected. Mortality rate varies randomly with age. People die of conditions other than old age. People surviving to old age are more hardy than expected.

Questions 87 – 89 Humans have been broadcasting signals into space since the invention of radio transmission approximately 100 years ago. There is now an expanding three-dimensional sphere or ‘bubble’ of radio and television signals radiating out from Earth. Television broadcasts are of greater energy than the older radio broadcasts. •

1 light year (the distance travelled by light in a year) is approximately 1 × 1016 m.

•

The speed of light is approximately 3 × 108 m s–1.

87

Which of the following is closest to the diameter of the radio bubble? A B C D

88

It would be difficult for any extraterrestrial life to detect these signals because the signals lose intensity at a rate inversely proportional to A B C D

89

1 × 1018 m 2 × 1018 m 3 × 1024 m 6 × 1024 m

the radius of the radio bubble. twice the radius of the radio bubble. the radius of the radio bubble squared. the radius of the radio bubble cubed.

Two signals (P and Q) of the same frequency are transmitted from Earth. Q has 100 times as much energy as P. Suppose there is a minimum intensity at which signals can be detected. Q can be detected up to A B C D

the same distance as P. 10 times as far as P. 100 times as far as P. 1000 times as far as P.

81

Questions 90 – 93 The figure below represents double-stranded DNA, which is composed of two strands base-paired by specific hydrogen bonds between A and T and between G and C. The strand on the left is arranged 5ʹ to 3ʹ from the top. The complementary strand on the right is in the reverse orientation (3ʹ to 5ʹ). 5'

O

O P O O

O

P

3'

O

N

A

N

N

O

N

NH2

O

O HN O

T

N

O

O

O O O N

C

O

3'

O

NH2

N

HN

NH2

O

P

O N

G

N N

O

O O

P

O O

O O

5'

The table below lists all possible double-stranded DNA sequences that are two base pairs in length.

First base pair

A T T A C G G C

A T 5' AA 3' 3' TT 5' 5' TA 3' 3' AT 5' 5' CA 3' 3' GT 5' 5' GA 3' 3' CT 5'

Second base pair T C A G 5' AT 3' 5' AC 3' 3' TA 5' 3' TG 5' 5' TT 3' 5' TC 3' 3' AA 5' 3' AG 5' 5' CT 3' 5' CC 3' 3' GA 5' 3' GG 5' 5' GT 3' 5' GC 3' 3' CA 5' 3' CG 5'

G C 5' AG 3' 3' TC 5' 5' TG 3' 3' AC 5' 5' CG 3' 3' GC 5' 5' GG 3' 3' CC 5'

Not all the two base-pair sequences in the table are different. A simple rotation shows that, for example, the following sequences are identical.

5′ CC 3′



and 3′ GG 5′



82

5′ GG 3′ 3′ CC 5′

90

Consider the single-stranded sequence 5′ GATATC 3′. Which one of the following sequences would base-pair with it? A B C D

91

92

Which one of the following represents identical double-stranded sequences? A

5′ CA 3′ 5′ CT 3′ and 3′ GA 5′ 3′ GT 5′

B

5′ TC 3′ 5′ TG 3′ and 3′ AC 5′ 3′ AG 5′

C

5′ AT 3′ 5′ TA 3′ and 3′ AT 5′ 3′ TA 5′

D

5′ AG 3′ 5′ CT 3′ and 3′ TC 5′ 3′ GA 5′

How many different double-stranded sequences containing only A and T are given in the table? A B C D

93

5′ GATATC 3′ 5′ CTATAG 3′ 3′ GATATC 5′ 3′ CATATG 5′

one two three four

A 16-residue, single-stranded DNA oligonucleotide is chemically synthesised with the following sequence. 5′ GTATAACCGGTTATAC 3′ Assume that any double-stranded DNA molecule conforming to the A–T and G–C base-pairing rules and with no mismatches can form. It is possible, given complementary sequences, for base-pairing to occur between single-stranded molecules and within a single-stranded molecule. In a solution containing strands of only this oligonucleotide, the longest double-stranded molecule that can form has A B C D

0 base pairs. 8 base pairs. 16 base pairs. 32 base pairs.

83

Questions 94 – 98 Gluten-induced coeliac disease (CD) is an autoimmune disorder that destroys the architecture of the small intestine. According to one theory, the following are crucial elements of an explanation. •

Unlike most proteins, gluten, rich in glutamine and proline, is not completely broken down to individual amino acids within the digestive system. This results in the presence of certain gluten peptides in the small intestine.

•

In people with CD, the intestinal wall is relatively permeable so that the peptides are not retained within the gut, but can leak across the lining where they stimulate the immune system. The increased permeability is due to a raised level of the protein zonulin, which has a similar effect to a cholera toxin in opening the tight junctions between the epithelial cells lining the gut.

•

As indigestible gluten peptides leak through and accumulate under the epithelial cells, they cause the release of IL-15, which arouses immune cells (intraepithelial lymphocytes), leading to damage of the epithelial cells and the release of the enzyme tissue transglutaminase (tTG) from them.

•

tTG attaches to and modifies the gluten peptides. The tTG-modified peptide groups form complexes with HLA-DQ2 or HLA-DQ8 proteins (especially common in people with CD). The complexes are displayed as antigens on the surface of antigen-presenting cells.

•

Helper T lymphocytes recognise the displayed antigens as a foreign material and cause the immune system to mount antibody attacks on tTG, gluten and complexes in the vicinity, and stimulate other immune responses, damaging intestinal cells. Damage leads to atrophy of the villi.

Within weeks of removal of gluten from the diet, intestinal damage begins to heal and autoimmune antibodies such as those against tTG and gluten peptides decline. Answer the following questions on the basis of the theory presented.

94

Which of the following best explains the occurrence of CD? A B C D

84

raised levels of intracellular tTG intestinal permeability to gluten peptides an abnormally functioning immune system the inability of some people to digest gluten

Questions 95 – 98 refer to the following additional information. For a population that is tested for CD by four methods using standard procedures and diagnosis thresholds, the following sensitivity and specificity values are obtained. Method

Sensitivity

Specificity

HLA-DQ2

95%

70%

HLA-DQ8

10%

80%

anti-tTG antibody

90%

95%

zonulin

100%

30%

Sensitivity =

Specificity =

TP TP + FN TN TN + FP

×

×

100 1 100 1

TP = true positive (number of sick people correctly diagnosed as sick) FP = false positive (number of healthy people incorrectly diagnosed as sick) TN = true negative (number of healthy people correctly diagnosed as healthy) FN = false negative (number of sick people incorrectly diagnosed as healthy)

95

Specificity indicates the percentage of A B C D

96

Of the following, which two methods produce the most false negatives and false positives, respectively? A B

97

HLA-DQ8 and zonulin zonulin and HLA-DQ8

C D

HLA-DQ2 and HLA-DQ8 HLA-DQ8 and HLA-DQ2

Compared with HLA-DQ2, using HLA-DQ8 diagnoses a greater proportion of A B C D

98

sick people correctly diagnosed as sick. healthy people incorrectly diagnosed as sick. sick people incorrectly diagnosed as healthy. healthy people correctly diagnosed as healthy.

all people as having CD. the people without CD as having CD. the people with CD as having the disease. the people with CD as not having the disease.

Compared with diagnosis using zonulin, diagnosis using anti-tTG antibody identifies a greater proportion of A B C D

all people as having CD. the people without CD as having CD. the people with CD as having the disease. the people with CD as not having the disease.

85

Questions 99 – 102 a-Amino acids have the general formula R-CH(COOH)-NH2. They can join together to form polypeptides, some of which act as hormones. The amino acids in the body are all a-amino acids and are in the zwitterion state, although this aspect is not considered in the following questions. While many polypeptide hormones are quite large molecules, some consist of just eight to ten amino acids. Two examples of nonapeptides in humans are argipressin, a hormone that controls blood pressure, and oxytocin, a hormone associated with childbirth. Similar nonapeptides are found in other animals. For example, octopuses have the hormones octopressin and cephalotocin. The orders of the nine amino acids that make up these hormones are shown below. argipressin

H2N-Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly-COOH

oxytocin H2N-Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-COOH octopressin H2N-Cys-Phe-Trp-Thr-Ser-Cys-Pro-Ile-Gly-COOH cephalotocin H2N-Cys-Tyr-Phe-Arg-Asn-Cys-Pro-Ile-Gly-COOH The convention for orienting peptides is to start on the left with the free amino group (-NH2) and to end at the right with the free carboxyl group (-COOH). The two cysteine residues in each nonapeptide usually form a disulfide bridge, but this can be ignored in the following questions. This table gives the name, abbreviation and R-group formula of some amino acids.

a-Amino acid

Formula of R group

Arg

arginine

-(CH2)3-NH-C(NH)-NH2

Asn

asparagine

-CH2-CO-NH2

Cys

cysteine

-CH2-SH

Gln

glutamine

-(CH2)2-CO-NH2

Gly

glycine

-H

Ile

isoleucine

-CH(CH3)-CH3

Leu

leucine

-CH2-CH(CH3)2

Lys

lysine

-(CH2)4-NH2

Phe

phenylalanine

-CH2-C6H5

Pro

proline

See below

Ser

serine

-CH2-OH

Thr

threonine

-CH(CH3)-OH

Trp

tryptophan

See below

Tyr

tyrosine

-CH2-C6H4-OH

CH2CHCOOH

COOH NH proline

86

NH2 NH tryptophan

In order to break apart or cleave a polypeptide in the laboratory, enzymes such as trypsin and chymotrypsin are used. Trypsin preferentially facilitates the cleavage of the peptide bonds at the carboxyl side of the amino acids lysine and arginine (except when either is followed by proline), whereas chymotrypsin facilitates the cleavage of the peptide bonds at the carboxyl side of the amino acids tyrosine, tryptophan and phenylalanine.

99

The cleavage of which of the four nonapeptides argipressin, oxytocin, octopressin and cephalotocin is facilitated by the enzyme trypsin? A B C D

argipressin but not oxytocin, octopressin or cephalotocin argipressin and cephalotocin but not oxytocin or octopressin oxytocin and octopressin but not argipressin or cephalotocin all four nonapeptides

100 Which amino acids could be isolated when chymotrypsin facilitates the cleavage of the nonapeptide argipressin? A B C D

phenylalanine but no others tyrosine and cysteine but no others tyrosine and phenylalanine but no others tyrosine, phenylalanine and cysteine but no others

101 What are the products when the cleavage of the nonapeptide cephalotocin is facilitated by the enzyme trypsin? A B C D

a single amino acid, a dipeptide and a hexapeptide two dipeptides and a pentapeptide a tripeptide and a hexapeptide a tetrapeptide and a pentapeptide

102 Suppose that for easier analysis argipressin is to be broken into units no longer than tripeptides. To do this, trypsin, chymotrypsin and one other enzyme are needed. This other enzyme should be able to cleave peptide bonds at the carboxyl side of A B C D

proline. cysteine. glutamine. phenylalanine.

87

Questions 103 and 104 Radioactive materials have characteristic half-lives. In general, a material with a short half-life releases energy more quickly than a material with a long half-life. If a radioactive material is introduced into the human body, the biological half-time is the time taken for the body to eliminate half the amount of radioactive material present at any time. The radioactive half-life of a particular material is independent of its biological half-time.

103 A radioactive material has a half-life of 10 minutes. How long will it take for 90% of the material to be transmuted? A B C D

between 0 and 10 minutes between 30 and 40 minutes between 40 and 50 minutes between 90 and 100 minutes

104 In order to undergo a scan, a patient is injected with a radioactive isotope that has a half-life of several days. If 1% of the isotope remains in the patient’s body between 13 and 14 hours later, which of the following is the best estimate of the biological half-time of the isotope? A B C D

1 hour 2 hours 3 hours 4 hours

Question 105

105 Making a few simple assumptions, which of the following is the best estimate of the rate at which your fingernails grow? A B C D

88

10–3 m s–1 10–6 m s–1 10–9 m s–1 10–12 m s–1

Questions 106 – 108 Optogenetics is the study of the interaction of light and genes, including the insertion of genes into cells to confer light responsiveness and the delivery of light to cells to activate certain responses. Historically, the observation of light-sensitive channel proteins in the membranes of certain cells was pivotal to the development of this field. For example, ChR2, a channel-forming protein, was found in the cell membrane of the algae Chlamydomonas. This protein responds to blue light by allowing sodium ions to pass through the cell membrane. ChR1 responds in the same way to yellow and green light, while NpHR responds to yellow light by allowing chloride ions to pass. The gene for such a light-sensitive protein can be inserted into mammalian cells, starting with the splicing of the gene, together with a promoter specific for a particular mammalian cell type, into the genetic material of a vector such as a benign virus. As a result of such work, investigators are now able to turn specific mammalian neuron types on and off.

106 How does the presence of a light-sensitive channel protein in the cell membrane activate a neuron? A B C D

It allows depolarisation. It allows the vector to enter the cell. It increases the production of synapses. It increases the storage of neurotransmitters in vesicles.

107 After gene insertion leading to the introduction of a light-sensitive channel protein into a mammal, which one of the following limits the cell types activated in response to light? A B C D

the type of vector the specific promoter the size of the channel protein the relative brightness of the light

108 How does gene insertion lead to cell activity related to light? A B C D

Cell metabolism is generally accelerated. The vector distributes the channel proteins. Specific enzyme production by cells is increased. The cell produces and incorporates the channel proteins.

89

Questions 109 and 110 The equations for the reactions of an acid (HA) and a base (B) with water, and their equilibrium constants (Ka and Kb respectively), are as follows:

HA + H2O

H3O+ + A−

Ka =

[H3O+] [A–] [HA]



B + H2O

BH+ + OH−

Kb =

[BH+] [OH–] [B]

The self-ionisation of water, and its equilibrium constant (Kw), is as follows: H3O+ + OH−

2 H2O

Kw = [H3O+] [OH–]

109 Which one of the following shows the relationship between Kb and [H3O+]? A

Kb =

Kw [BH+] [H3O+] [B]

C

Kb =

Kw [B] [H3O+] [BH+]

B

Kb =

[BH+] Kw [H3O+] [B]

D

Kb =

[B] Kw [H3O+] [BH+]

110 Because

pKa = −log10 Ka  and  pH = −log10 [H3O+],

pKa = pH − log10 

[A−] [HA].

Which of the following expresses pKb?

90

A

pKb = pKw + pH − log10 

[BH+] [B]

C

pKb = pH − pKw − log10 

[BH+] [B]

B

pKb = pKw − pH − log10 

[BH+] [B]

D

pKb = −pH − pKw − log10 

[BH+] [B]

Notes on Assessment of Written Communication The Written Communication section of GAMSAT is a test of the ability to produce and develop ideas in writing. It involves two thirty-minute writing tasks. Each task offers a number of ideas relating to a common theme. The theme will be general rather than specific in nature. The first task deals with socio-cultural issues while the second deals with more personal and social issues. In selecting topics for the writing tasks every effort is made to minimise factors that might disadvantage candidates from non-English-speaking backgrounds. Performances on the Written Communication section of GAMSAT are assessed against the criteria shown below. Markers take into account both the quality of a candidate’s thinking about a topic and the control of language demonstrated in the development of a piece of writing. Although both these factors are important, more emphasis is given to generative thinking (thought and content) than to control of language (organisation and expression). Candidates are not assessed on the basis of the views they express but on the complexity and sophistication of their discussion.

CRITERIA FOR THE ASSESSMENT OF GAMSAT WRITING THOUGHT AND CONTENT (the quality of what is said) •

what is made of and developed from the task

•

the kinds of thoughts and feelings offered in response to the task

ORGANISATION AND EXPRESSION (the quality of the structure developed and the language used) •

the shape and form of the piece

•

the effectiveness and fluency of the language

91

Answers to Multiple Choice Questions Reasoning in Humanities and Social Sciences 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

D A B C B A B A B D C A C C B C B D B D B

22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

B A D A B C D C C C B C A A B C C D A B A

43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

D A D B A D D B A B B D D A D A D C D A A

64 65 66 67 68 69 70 71 72 73 74 75

C A C D B A C D B B B A

91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110

D C C B D A D D B A D B B B C A B D A B

Reasoning in Biological and Physical Sciences 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

92

B D B D D C A C D B A A C A C B B C D C C A C C C C B A D D

31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

B B C B D C B C B C B C C D A A A A B C A A A D C A B C A B

61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90

B B A A B C D D A B D D D C A A B D B D B C C A A D B C B A

Acknowledgements Reasoning in Humanities and Social Sciences pp. 8–9: Copyright Siegfried Sassoon by kind permission of the Estate of George Sassoon; p. 9: Hugh MacDiarmid, Selected Poems, Carcanet Press Limited, 2006; p. 16. The Screwtape Letters by C.S. Lewis. Copyright © C.S. Lewis Pty. Ltd. 1942. Extract reprinted by permission; p. 17: Frank Cotham/The New Yorker Collection/The Cartoon Bank; p. 20. from ‘Finding a Right to Be Tortured’ by John T. Parry, in Law and Literature, Volume 19, No.2, 2007. Copyright © Cardozo School of Law. Reprinted by permission of Taylor & Francis Ltd, http://www.tandfonline. com, on behalf of Cardozo School of Law. p. 26: from ‘Expert Medico-Scientific Evidence before Tribunals: Approaches to Proof, Expertise and Conflicting Opinions’, by Randall Kune and Professor Gabriel Kune in the Australian Journal of Administrative Law, Volume 13, 2006. Reproduced with permission of Thomson Reuters (Professional) Australia Limited, www. thomsonreuters.com.au; p. 28: Labonte, R. ‘Heart health inequalities in Canada: modules, theory and planning’ in Health Promotion International, Volume 7, Issue 2, pp.119–128, reproduced by permission of Oxford University Press; p. 29: Edward Koren/The New Yorker Collection/The Cartoon Bank; p. 30: from A Spot of Bother by Mark Haddon, published by Jonathan Cape. Reprinted by permission of The Random House Group Limited; Belling, Catherine. ‘Hypochondriac Hermeneutics: Medicine and the Anxiety of Interpretation.’ Literature and Medicine 25:2 (2006), 376–377, 380. © 2007 by The Johns Hopkins University Press. Reprinted with permission of The Johns Hopkins University Press; p. 32: copyright Patrick White 1961; p. 34: Noam Chomsky ‘The Case Against B.F. Skinner’, New York Review of Books, 1971 © Noam Chomsky.

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