AIIMS Model Paper 2015

1. Two different animals are classified into the same family. This means that they would be classified in
(a) the same phylum but different class
(b) the same class but different species
(c) a different kingdom and different phylum
(d) a different class and different order.
2. The amount of DNA in a cell can be determined by measuring the fluorescence of a dye that binds in direct proportion to the amount of DNA. The histogram below represents the fluorescence of an eukaryotic germ cell during different stages of cell division (I, II, III, IV and V).

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Which of the following sequences represents the correct match of stages I-V with the division stages numbered 1 – 5?
1. Anaphase-I of meiosis
2. Anaphase-II of meiosis
3. Cytokinesis following telophase-II
4. Prophase-II of meiosis
5. Prophase-I of meiosis

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3. The characteristic cell wall material peptidoglycan has another covering of lipopolysaccharides. This specialized condition is found in (a) Gram +ve eubacteria
(b) Gram-ve eubacteria
(c) all eukaryotes (d) both (a) and (b).
4. Sometimes a ladder-like structure observed in Spirogyra is formed due to
(a) lateral conjugation (b) direct conjugation
(c) scalariform conjugation
(d) asexual reproduction.
5. Glyceraldehyde phosphate is oxidized during glycolysis. What happens to the hydrogen atom and the electron that are removed during oxidation?
(a) They reduce NAD+.
(b) They oxidise NAD+.
(c) They are transferred to pyruvic acid.
(d) They are eliminated in the form of methane.
6. Which of the following is an example of a conjugated protein?
(a) Casein (b) Serum albumin
(c) Globulin (d) Histones
7. Which of the following statements is incorrect?
(a) During the process of exocytosis, the lumen (inner) surface of a secretory vesicle becomes the inside of the plasma (cell) membrane.
(b) Cilia, microtubules and flagella are all associated with movement in cells.
(c) A function of the nucleus is duplicating the genes for cell division.
(d) Proteins that are to be secreted by cell are generally synthesized by ribosomes.
8. Study the two cases

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(a) Case I : X-linked recessive disease
Case II : Autosomal recessive disease
(b) Case I : Y-linked recessive disease
Case II : X-linked recessive disease
(c) Case I and II : X-linked recessive disease
(d) Case I : X-linked dominant disease
Case II : Autosomal dominant disease.
9. Last electron acceptor in ETS is
(a) O2 (b) CoQ
(c) cytochrome c (d) cytochrome a3.
10. Match column – I with column – II and select the correct option from the codes given below.

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11. Select the correct statement out of the following.
(a) Healing of damaged tissue is because of the activity of sclerenchyma cells.
(b) Grafting is difficult in monocot plants as they have scattered vascular bundles.
(c) Because of marked climatic variations, plants growing near the sea shore do not produce annual rings.
(d) The age of the plant can be determined by its height.
12. Out of 5 petals of a flower bud, two are completely internal, two are completely external and the remaining one is at its margin, internal as well as external. Identify this type of aestivation.
(a) Imbricate (b) Valvate
(c) Vexillary (d) Quincuncial
13. What differentiates PS I from PS II in photochemical reaction of photosynthesis?
(a) Production of NADPH2
(b) Production of ATP
(c) Being non-cyclic
(d) All of the above

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17. When two different species associate with each other for the benefit of both, it is termed as positive interaction. Which of the following is generally not a positive interaction?
(a) Flower and nectarivore
(b) Plant and herbivore
(c) Leguminous plant and nitrogen fixing bacterium
(d) A lichen

18. If you were outside for a long time on a hot, dry day, without anything to drink, which of the following would happen?
(a) The production of thyroxine by thyroid gland would increase.
(b) The osmotic pressure of blood would decrease.
(c) The re-absorption of fluids from kidney tubules would decrease.
(d) The secretion of anti-diuretic hormone from pituitary gland would increase.
19. The given figure represents internal body plan of 1
(a) Platyhelminthes
(b) Nematoda
(c) Annelida
(d) Echinodermata.

20. The number of chromosomes present in the cells of the bread wheat Triticum aestivum suggest that it is
(a) hexaploid (b) diploid
(c) tetraploid (d) pentaploid.
21. The figure shows the restriction enzyme cutting sites
(R1 – R3) in a wild type (n) and mutant (n) gene.

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If a radioactively labelled probe (that hybridizes at a sequence close to R1) is used for detecting the presence of DNA fragments after gel electrophoresis and Southern blotting, which of the following band patterns will you expect? (L1: wild type DNA, L2 : mutant DNA)

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22. A codon consists of 3 bases and there are of 4 different kinds of bases in a nucleic acid altogether. How many codons will be there?
(a) 64 (b) 86 (c) 22 (d) 60
23. Select the correct statement out of following.
(a) mRNA is polycistronic in eukaryotes and monocistronic in prokaryotes
(b) mRNA is polycistronic in prokaryotes and monocistronic in eukaryotes
(c) mRNA is polycistronic in both eukaryotes and prokaryotes
(d) mRNA is monocistronic in both eukaryotes and prokaryotes
24. In the pedigree shown in the figure, individuals with the solid symbols suffer from a genetic disease caused by a recessive allele at an autosomal locus. You would counsel the couple marked A and B that the probability that each of their children will have the disease is

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25. Smoking induces degenerative changes in the lining of trachea. The epithelial cells most affected are
(a) columnar (b) ciliated
(c) glandular (d) stratified.
26. Given diagram shows bone1
of the left human hindlimb as
seen from front. It has certain
mistakes in labelling. Two of
the wrongly labelled bones
are
(a) tibia and fibula
(b) femur and fibula
(c) fibula and phalanges
(d) phalanges and metatarsals.

27. Which of the following is incorrectly paired with its function?
(a) Small intestine – enzymatic digestion of lipids, proteins and polysaccharides
(b) Oesophagus – transports food from the mouth to the stomach
(c) Large intestine – chemical breakdown of undigested starch, fats and amino acids
(d) Stomach – mechanical and chemical digestion of food
28. Mammalian lungs have an enormous number of minute alveoli (air sacs). This is to allow
(a) more surface area for diffusion of gases
(b) more space for increasing the volume of inspired air
(c) more nerve supply to keep the lungs working
(d) more spongy texture for keeping lung in proper shape.
29. The mammalian heart beat
(a) stops when the nerve supply to the heart is cut
(b) originates at the atrioventricular node
(c) decreases when stretch receptors in the vena cava are stimulated
(d) slows down when activity in the vagus nerve increases.
30. Vaccines produced through genetic engineering are safe as
(a) they contain antigen only from coat of pathogen
(b) they are least active form of virus
(c) they are attenuated form of pathogen
(d) all of the above.
31. Given below is a diagrammatic sketch of a portion of human male reproductive system. Select the correct set of the names of the parts labelled A, B, C, D.

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(a) A-vas deferens, B-seminal vesicle, C-prostate, D-bulbourethral gland
(b) A-vas deferens, B-seminal vesicle, C-bulbourethral gland, D-prostate
(c) A-ureter, B-seminal vesicle, C-prostate, D-bulbourethral gland
(d) A-ureter, B-prostate, C-seminal vesicle, D-bulbourethral gland
32. Read the following statements and select the correct ones.
(i) Medical termination of pregnancy (MTP) during first trimester is generally safe.
(ii) Generally chances of conception are nil until mother breast-feeds the infant upto two years.
(iii) Intrauterine devices like copper-T are effective contraceptives.
(iv) Contraceptive pills may be taken upto one week after coitus to prevent conception.
(a) (i) and (iii) (b) (i) and (ii)
(c) (ii) and (iii) (d) (iii) and (iv)
33. In a car accident, a person has the sensory neurons to his hand severed with no other damage being recorded. This person will
(a) regain feeling as the motor neurons will adapt and carry sensory impulses
(b) be unable to feel and move his hand as feeling and movement is carried by the same neurons
(c) regain feeling as the motor nerves replicate and replace the damaged neurons
(d) be unlikely to regain feeling in the hand but will be able to move it.
34. A biologist sequenced the cytochrome-c enzyme in a range of animals and compared the amino acid (AA) differences between pairs of species. Which of the following results would be most consistent with modern systematics?

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36. Roots of which of the following species contain valuable alkaloids that are useful in medicine?
(a) Rauwolfia serpentina
(b) Asparagus officinalis
(c) Emblica officinalis (d) Helianthus annuus
37. On which part of the brain a ‘drunk person’ has the earliest effect?
(a) Cerebrum (b) Pons varolii
(c) Cerebellum (d) Medulla oblongata
38. If we completely remove the decomposers, from an ecosystem, its functioning will be adversely affected, because
(a) energy flow will be blocked
(b) mineral movement will be blocked
(c) herbivores will not receive solar energy
(d) rate of decomposition will be very high.
39. Read the following statements regarding replication of a DNA and transcription and select the correct ones.
(i) During the replication even the introns are replicated, whereas introns are not transcribed during the process of transcription.
(ii) Some of the bases that are incorporated during replication differ from those that are incorporated during transcription.
(iii) There is no need of unwinding of strands during transcription, whereas replication process needs the unwinding of DNA strands.
(iv) DNA-RNA hybrid is formed at some stage during both the processes.
(a) (i) and (ii) (b) (ii) and (iii)
(c) (iii) and (iv) (d) (ii) and (iv)
40. Match the following and select the correct option from the codes given below.

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Direction : In the following questions (41-60), a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as :
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.
41. Assertion : As electrons move through photosystems, protons are transported across the membrane.
Reason : Primary accepter of electron, located on outer side of membrane, transfers its electron to a H– carrier while removing the proton.
42. Assertion : Alpha – diversity is also known as within community diversity.
Reason : It is dependent upon species richness and evenness.
43. Assertion : Active water absorption by roots needs metabolic energy.
Reason : Passive water absorption by roots occurs in response to transpiration.
44. Assertion : Photorespiration is a wasteful process in C3 plants.
Reason : During photorespiration, no energy is produced and 25% of fixed CO2 is lost.
45. Assertion : Ovule has a protective envelope called integument.
Reason : Integument encircles the ovule completely.
46. Assertion : Nuclear endosperm is formed by subsequent nuclear division without wall formation.
Reason : Coconut is an example of such endosperm, where the endosperm remains nuclear throughout the development of the fruit.
47. Assertion : Cytokinins are antisenescent.
Reason : Cytokinins have been found to induce flowering in certain species of plants.
48. Assertion : Primary succession takes a very long time.
Reason : Succession taking place after forest fire is called primary succession.
49. Assertion : Use of weedicides affects photosynthetic ability of plants.
Reason : Weedicides are metabolic inhibitors.
50. Assertion : In human, insulin is synthesised as a prohormone.
Reason : Pro-hormone needs to be processed before it becomes a fully mature and functional hormone.
51. Assertion : In coelenterates, the arrangement of cells is complex.
Reason : The cells performing the same functions are arranged into the tissues.
52. Assertion : The cells of columnar epithelium at absorptive surfaces often bear microvilli on their free ends.
Reason : Microvilli enhance surface area for absorption.
53. Assertion : Thyroid gland is a ductless gland.
Reason : Thyroid gland directly pours its secretion i.e. thyroxine, into the blood.
54. Assertion : The normal heart rate is 72/min and the duration of cardiac cycle is 0.8 sec.
Reason : The duration of cardiac cycle is inversely proportional to the heart rate.
55. Assertion : The space between the seminiferous tubules is occupied by Sertoli cells.
Reason : Sertoli cells secrete testosterone hormone.
56. Assertion : Head of the sperm consists of acrosome and mitochondria.
Reason : Acrosome contains spiral row of mitochondria.
57. Assertion : Excessive amounts of calcitonin hormone in the blood causes softening of bones.
Reason : Calcitonin causes mobilisation of calcium from the bones to the blood plasma.
58. Assertion : Lac operon is an example of inducible operon system.
Reason : In this, the product of gene activity, if already present, stops the activity of concerned gene.
60. Assertion (A) : Test cross is a type of back cross
Reason (R) : Test cross is used to know whether an individual is homozygous or heterozygous.

1. (b) 2. (a) 3. (b) 4. (c) 5. (a)
6. (a) 7. (a) 8. (a) 9. (a) 10. (a)
11. (c) 12. (d) 13. (a) 14. (a) 15. (a)
16. (a) 17. (b) 18. (d) 19. (b) 20. (a)
21. (c) 22. (a) 23. (b) 24. (c) 25. (b)
26. (d) 27. (c) 28. (a) 29. (d) 30. (a)
31. (a) 32. (a) 33. (d) 34. (d) 35. (c)
36. (a) 37. (a) 38. (b) 39. (d) 40. (c)
41. (a) 42. (b) 43. (b) 44. (a) 45. (c)
46. (c) 47. (b) 48. (c) 49. (a) 50. (b)
51. (a) 52. (a) 53. (a) 54. (b) 55. (d)
56. (d) 57. (d) 58. (c) 59. (d) 60. (b)  

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