AIIMS Practice Paper Biology – 1

1. Female external genitalia includes a structure which is homologous with the penis of male …………..

(a) Labia minora

(b) Labia majora

(d) Mons veneris

Answer: (c)

Solution

Self Explanatory

2. Drones in a colony of honey bees originate by

(a) Cyclic Parthenogenesis

(b) Thelytoky

(d) Diploid Parthenogenesis

Answer: (c)

Solution

Arrhenotoky is a type of parthenogenesis in which the unfertilized eggs develop into males with haploid cells.

3. Testosterone is produced by ……….

(a) Hypothalamus

(b) Interstitial cells

(d) Sertoli cells

Answer: (b)

Self Explanatory

Solution

4. A cross section of human sperm at midpoint of middle piece shows

(a) mitochondria and 7 + 2 arrangement of microtubules

(b) mitochondria and 9 + 2 arrangement of microtubules

(d) centrioles , mitochondria and 7 + 2 arrangement of microtubules.

Answer: (b)

Solution

Middle piece contain mitochondria and axial filament. Axial filament has 9 + 2 arrange of microtubule

5. Mesolecithal egg shows the cleavage

(a) holoblastic and unequal

(b) holoblastic and equal

(d) discoidal

Answer: (a)

Solution

Mesolecithal egg contain moderate amount of yolk. So cleavage is holoblastic & unequal.

Example; Petromyzon, frog

6. National parks and Biosphere Reserve are

(a) In – Situ conservation

(b) Ex – Situ conservation

(d) None of these

Answer: (a)

Solution

The conservation of habitats and ecosystems where organisms naturally occur is called In – situ conservation like national parks, wildlife sanctuaries.

7. Administration of antivenom is

(a) Artificially acquired active immunity

(b) Artificially acquired passive immunity

(d) Naturally acquired active immunity

Answer: (b)

Solution

Artificial passive immunity is the resistance passively transferred to a recipient by administration of antibodies like administration of antivenom.

8. Cornea transplantation is popular as ………

(a) It is easily available

(b) Easily transplanted

(d) None of the above

Answer: (c)

Solution

Only fibre consumption.

9. Antibodies present in colostrums which protect the new born from certain diseases is of

(a) Ig G type

(b) Ig A type

(d) Ig E type

Answer: (b)

Solution

Only antibody in milk.

10. A person with sickle cell anaemia is …………….

(a) More prone to malaria

(b) Less prone to malaria

(d) More prone to typhoid

Answer: (b)

Solution

Malaria parasite can’t grow in sickle cell.

11. The disease chikunguniya is transmitted by:

(a) House fly

(b) Aedes mosquito

(d) Female Anopheleles

Answer: (b)

Solution

Self Explanatory

12. Opium is obtained from

(a) Oryza sativa

(b) coffea arabica

(d) Papaver somniferum

Answer: (d)

Solution

Self Explanatory

13. The Hybridoma technology is involved in production of

(a) Monoclonal antibodies

(b) Polyclonal antibodies

(d) None of these

Answer: (a)

Solution

Hybridomas are somatic cells hybrids produced by fusing antibodies forming spleen cells with myeloma cells.

14. In RNAi, genes are silenced using:

(a) Ss DNA

(b) ds DNA

(d) ss RNA

Answer: (c)

Solution

Complementarity.

15. Volume of air breathed in and out, while at rest is called

(a) vital volume

(b) tidal volume

(d) total lung capacity

Answer: (b)

Solution

Tidal volume is the volume of air inspired or expired with each normal breath. This is about 500 ml in adult person.

16. In normal healthy man bone marrow is

(a) 1000ml

(b) 2000ml

(d) 4000ml

Answer: (d)

Solution

Self explanatory

17. A protein that is both structural and catalytic is

(a) Actin

(b) Myosin

(d) insulin

Answer: (b)

Solution

Usually proteins are structural, catalytic or receptos. But this uses the stored energy of ATP.

18. A muscle fibre is an example of

(a) a single cell

(b) tissue

(d) mesokaryon

Answer: (c)

Solution

A muscle cell is formed due to fusion of about 50 mesnchymal cells in embryonic stage of life.

19. The emotional brain refers to the—- of brain.

(a) the limbic system

(b) the sensory system

(d) None of the above

Answer: (a)

Solution

The limbic system controls anger, emotions, memory etc.

20. Arteriosclerosis causes hypertension by

(a) reducing the lumen of arteries due to fibrosis

(b) reducing the lumen due to cholesterol

(d) None of the above

Answer: (a)

It is a disease due to loss of elasticity of collagen fibres on the blood vessels.

Solution

21. How does sweating cool down the body

(a) By losing water

(b) By chilling the skin

(d) By losing salt

Answer: (c)

22. ………………… produce 3 categories of sounds: clicks, whistles and pulsed calls.

(a) Carnivora

(b) Chiroptera

(d) Cetacea

Answer: (d)

Solution

Cetaceans depend heavily on under water sound for orientation / navigation, feeding and communication/ social interactions.

23. Which of the following causes water pollution …………..

(a) 2,4- d and pesticides

(b) Smoke

(d) Aeroplanes

Answer: (a)

Solution

Both are soluble.

24. The word ecosystem was coined by …………..

(a) Weaver & Clements

(b) A.G. Tansley

(d) E.P. Odum

Answer: (b)

Solution

Self Explanatory

25. The association between Hydra & Zoo chlorelles are

(a) Commensalism

(b) Symbiosis

(d) Saprophytic

Answer: (a)

Solution

Commensalism is the association between two species in which one gets the benefit and the other is neither benefited nor harmed.

26. For chlamydomonas which one is correct

(a) Unicellular, Phaeophyceae & show isogamous reproduction.

(b) Multicellular, BGA & show oogamous reproduction.

(d) Acellular, Pheophyceae & oogamous reproduction.

Answer: (c)

Solution

Because Chlamydomonas is unicellular algae belongs to Chlorophyceae & it shows anisogamous type of reproduction because the fusion of two gamates takes place which are dissimilar in size.

27. Which one is correct?

A. Cephaleuros virescens causes red rust of tea.

B. Ectocarpus causes the water bloom in rainy season.

C. Oscillatoria deplete the water of O₂ and hence animals like fish are killed.

D. Chlorell a (green algae) is used in Nucles – cyloplasmic interaction research.

(a) All of these are correct

(b) A is False & B, C, D are correct

(d) A & C are correct

Answer: (d)

Solution

Blue green algae and Gree algae cuases water bloom in rainy season. Acetabularia and valonia is used in research of Nucleo – cytoplasmic interaction.

28. The reserve food material found in red algae is:

(a) Myxophycean starch

(b) Laminarin & manitol

(d) None of these

Answer: (c)

Solution

Floridian starch is a polysaccharide found commonly in red algae as food reserve / Red algae belong to algal class Rhodophyta and are the rich source of agar and carrageen / Play major Role in the formation of coral reef in Ocean bead.

29. Proteinaceous bodies that serve as the sites for starch formation in algae are:

(a) Chromatophore

(b) Chloroplast

(d) Pyrenoid

Answer: (d)

Solution

Pyrenoids are the protein bodies which are the center for CO₂ fixation within the chloroplast of algae and hornworts / They are not membrane bounded, but specialized areas of plastid that contain huge amount of ribulose-1,5 bisphosphate carboxylase / oxygenase (Rubisco).

30. Sexual reproduction is algae is stimulated by :

(a) Nitrogen deficiency

(b) Alkaline pH of surrounding medium

(d) All of these

Answer: (d)

Solution

Algae show wide range of sexual reproduction that ranges from most primitive isogamy to the most advanced oogamy.

31. Bacterial plasma membrane is composed of:

(a) Glycoprotein

(b) Nucleo-protein

(d) Lamins

Answer: (c)

Solution

Like eukaryotic plasma membrane, bacterial plasma membrane is also made of lipids and proteins.

32. Swarming stage is not found in the life cycle of:

(a) Chlamydomonas

(b) Funaria

(d) Agaricus

Answer: (d)

Solution

In Agaricus no motile cells found in the life cycle

33. In ferns, both antheridia and archegonia are found in:

(a) Sporophylls

(b) Sorus

(d) Prothallus

Answer: (d)

Solution

Prothallus is the gametophyte of ferns. It is monoecious, having antheridia intermingled with rhizoids in the basal region and archegonia in the notch region.

34. Genetic material is found in the cytoplasm without cover in the cells of:

(a) Mycoplasma and Chlorella

(b) Escherichia coli and Puccinia

(d) None of the these

Answer: (c)

Solution

Prokaryotic chromosome/circular DNA floats in the general cytoplasm, and the region is called nucleoid.

35. Manoxylic wood is:

(a) Compact, nonporous and hard wood

(b) Loose, porous and soft wood

(d) Derived from persistent cambium

Answer: (b)

Solution

Manoxylic wood is observed in a group of gymnosperm called Cycadophyta / Soft and porous wood hence commercially useless.

36. Honey or nectar is the richest source of:

(a) Glucose

(b) Fructose

(d) None of these

Answer: (b)

Solution

Fructose or fruit sugar is the major chemical constituent of honey that forms 40% of total honey.

37. Margarine and vanaspati ghee are the solid fats produced by a type of reaction called:

(a) Condensation

(b) Oxidation

(d) Hydrogenation

Answer: (d)

Solution

Hydrogenation converts liquid vegetable oils into solid or semi-solid fats, such as those present in margarine and vanaspati / Hydrogenation of unsaturated fats produces saturated fats and, in some cases, trans fats.

38. Conjugate Lipids found in Myelin sheath of modulated nerve fiber are:

(a) Cerebrosides

(b) Sphingomyelins

(d) All of these

Answer: (a)

Solution

Cerebrosides is a group of glycosphingolipid called monoglycosylceramides which are important components in animal muscle and nerve cell membranes.

39. Microbody which is located in between cell membrane and cell wall of fungi & concerned with deposition of wall materials is:

(a) Sphaerosome

(b) Lomasome

(d) Glyoxysome

Answer: (b)

Solution

Lomasomes are the extensions of ER that carry out deposition of chitin over the cell wall of fungi.

40. Meiosis is characteristically observed in angiosperms at the time of:

(a) Asexual reproduction

(b) Sexual reproduction

(d) None of these

Answer: (a)

Solution

Meiosis is concerned with sporogenesis in plants and gametogenesis in animals / Sporogenesis is the part of asexual reproduction and gametogenesis is the part of sexual reproduction.

41. During fruit ripening the skin of the fruit became yellow and soft. Softening of skin occurs due to the disintegration of:

(a) Primary cell wall

(b) Secondary cell wall

(d) None of these

Answer: (c)

Solution

Middle lamella is chemically composed of Ca⁺⁺, Mg⁺⁺ and pectin. During fruit ripening excess synthesis of enzymes like cellulase and pectinase cause disintegration of middle lamella resulting in softening of skin.

42. The extended part of endoplasmic reticulum into the pit chamber that helps in inter cellular transportation of materials is called:

(a) Cisternae

(b) Desmosome

(d) Desmotubule

Answer: (d)

Solution

Part of ER present within the pit chamber along with plasmodesmata /Take part in exchange of materials in between adjacent cells.

43. The smallest and largest cell structures are found respectively in:

(a) Bacteria and Acetabularia among plants

(b) Mycoplasma and Egg of Ostrich among animals

(d) Both a and b

Answer: (d)

Solution

Bacteria and Mycoplasma (PPLO) are the smallest plant and animal cell respectively where as Acetabularia and egg of Ostrich are the largest plant and animal cell respectively.

44. The Latin statement “Omnis cellula-e-cellula” is a part of the theory called:

(a) Cell theory

(b) Protoplasmic theory

(d) Theory of cell lineage

Answer: (d)

Solution

The above statement is originally given by Rudolf Virchow in his “Theory of cell lineage” that means “Each cell is originated from a preexisting cell.

45. An incipient nucleus is characterised by the absence of:

(a) Chromosome

(b) Nucleolus and nuclear membrane

(d) Microtubules

Answer: (b)

Solution

Incipient nucleus is the most primitive type of nucleus as observed in lower organism like Bacteria.

46. “Cauliflory” means :

(a) Production of flowers on old stem

(b) Flowers on young branches

(d) Flowers in clusters

Answer: (a)

Solution

Cauliflory refers to plants which flower and fruit from their main stems or woody trunks rather than from new growth and shoots / Observed in plants like Fig wood, Rose Apple, Jackfruit, Yellow Mahogany etc.

47. Bacteria which are most commonly employed in genetic engineering tech. is :

(a) Pseudomonas & E. coli

(b) Thermococcus & Pyrococcus

(d) None of these

Answer: (c)

Solution

Agrobacterium tumefaciens and A. rhizogenes are commonly used in genetic engineering as the biological vector for gene transfer / E. coli is used as a biological cloning vector for isolated gene (DNA segment) for the construction of gene library.

48. ELISA involves use of enzyme :

(a) Alkaline phosphatase

(b) Horse radish Peroxidase

(d) Any one

Answer: (d)

Solution

Enzyme-linked immunosorbent assay (ELISA) is a test that uses antibodies and color change to identify a substance / ELISA is performed to evaluate the presence of antigen or antibody in a sample and it is a useful tool for determining serum antibody concentrations used in HIV test or in food industry in detecting potential food allergens.

49. Synthetic growth inhibitor that inhibits sprouting of potato tuber is:

(a) Morphactin

(b) Chlormequat

(d) None of these

Answer: (c)

Solution

Maleic hydrazide has been introduced into agriculture as a major commercial herbicide and a depressant of plant growth in numerous circumstances such as suppression of storage sprouting of vegetables and food crops, retardation of flowering and prolongation of seed dormancy.

50. Which of the followings is wrong about crossing experiments conducted in genetics:

(a) Crossing performed by assuming a single pair of contrasting character is called monohybrid cross

(b) Crossing performed by assuming two pairs of contrasting character is called dihybrid cross

(d) None of these

Answer: (c)

Solution

Test cross is a type of back cross which is performed to verify whether the parents are homozygous or not. In test cross, the F₁hybrid is crossed with the recessive parent. The ratio for a monohybrid test cross remains 1: 1.

51. Assertion: Mosses are evolved from algae.

Reason: Protonema of mosses is similar to some green algae.

(a) If both the Assertion and Reason are true and Reason is the correct explanation of the Assertion.

(b) If both the Assertion and Reason are true but the Reason is not correct explanation of the Assertion.

(d) If the Assertion is false but the Reason is true.

Answer: (a)

Solution

According to some botanists, mosses originated from algae. Protonema of mosses is similar to certain algae.

52. Assertion: Many plants are propagated vegetatively even though they bear seeds.

Reason: Potatos multiply by tubers, apple by cutting etc.

(a) If both the assertion and reason are true and reason is the correct explanation of the assertion.

(b) If both the assertion and reason are true but the reason is not correct explanation of the assertion.

(d) If the assertion is false but the reason is true.

Answer: (b)

Solution

Vegetative reproduction is asexual type of reproduction potato, sugarcane, apple etc., are multiplied by axesual means.

53. Assertion: The two cotyledons in seed are embryonic leaves.

Reason: The embryo contain radicle and plumule.

(a) If both the assertion and reason are true and reason is the correct explanation of the assertion.

(b) If both the assertion and reason are true but the reason is not correct explanation of the assertion.

(d) If the assertion is false but the reason is true.

Answer: (b)

Solution

In angiospermic seeds, cotyledons are embryonic leaves. Embryo also has radicle and plumule which gives rise to root and shoot respectively.

54. Assertion: Systematics is the branch of biology that deals with classification of living organisms.

Reason: The aim of classification is to group the organisms.

(a) If both the assertion and reason are true and reason is the correct explanation of the assertion.

(b) If both the assertion and reason are true but the reason is not correct explanation of the assertion.

(d) If the assertion is false but the reason is true.

Answer: (b)

Solution

Systematics is related with classification of organisms. In classification, the organism are grouped on the basis of their characters or phylogeny etc.

55. Assertion : Smaller the organism higher is the rate of metabolism per gram weight.

Reason : The heart rate of a six month old baby is much higher than that of an old person.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion.

(d) If both assertion and reason are false.

Answer: (a)

Solution

In smaller organisms the rate of metabolism is higher in comparison to adult one. For example the average heart rate per minute in new born baby is 130 while in 75 years and above aged person it is only 75.

56. Assertion : Organochlorine pesticides are organic compounds that have been chlorinated.

Reason : Fenitrothion is one of the organochlorine pesticides.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion.

(d) If both assertion and reason are false.

Answer: (c)

Solution

Pesticides are the substances used to kill or repel pests. On the basis of chemical structure, major pesticides are grouped under five categories : (i) organochlorines (ii) organophosphates (iii) carbamates (iv) pyrethroids (v) triazines. Organochlorines are basically organic compounds that have been chlorinated and have very low bio-degradation and get accumulated in environment and possess serious problems. DDT, BHC, aldrin and endosulphan are the examples of organophosphate.

57. Assertion : Diabetes insipidus is marked by excessive urination and too much thirst of water.

Reason : Antidiuretic hormone (ADH) is secreted by posterior lobe of pituitary gland.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion.

(d) If both assertion and reason are false.

Answer: (b)

Solution

Antidiuretic hormone (ADH) or vasopressin is secreted by the posterior lobe (neurohypophysis) of pituitary gland, hyposecretion of ADH results in diabetes insipidus which is characterized by micturating dilute urine several times a day and excessive thirst.

58. Assertion : Coacervates are believed to be precursors of life.

Reason : Coacervates were self – duplicating aggregates of proteins surrounded by lipid molecules.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion.

(d) If both assertion and reason are false.

Answer: (b)

Solution

Coacervates are short spherical 1 to 2 micrometer in diameter molecules, formed in primitive ocean sonp. These mainly contain protein, polysaccharides, water and outer covering of lipid molecules. Coacervates grow by accumulating more subunit molecules from the surrounding medium.

59. Assertion : In recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeast (eukaryotes).

Reason : Both bacteria and yeast multiply very fast to form huge population which express the desired gene.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion.

(d) If both assertion and reason are false.

Answer: (a)

Solution

Recombinant DNA is the DNA whose nucleotide sequence has undergone alteration as a result of incorporation or exchange with another DNA strand. In recombinant DNA technology, human genes are often transferred into bacterial or yeast because both bacteria and yeast multiply very fast to form huge population which express the desired gene.

60. Assertion : Cancer cells are virtually immortal until the body in which they resides dies.

Reason : Cancer is caused by damage to genes regulating the cell division cycle.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion

(d) If both assertion and reason are false.

Answer: (a)

Solution

Cancer is caused by damage to genes regulating the cell division cycle.

It is an uncontrolled proliferation of the cells. All types of cancer have five basic characteristics :

(a) Uncontrolled cell growth.

(b) Loss of ell differentiation (specialization).

(d) Metastasis or spread to multiple sites.

(e) Loss of contact inhibition.

All these characteristics make the cancer importal until the body in which it resides dies.

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