ZOOLOGY

UPSC CSE Mains Zoology Syllabus

Answer the following type of questions Assertion (A) and Reason (R)
a. A and R are true, R is the correct explanation of A
b. A and R are true, R is not the correct explanation of A
c. A is true, R is false d. Both A and R are false

1. A – In human male, testes are extra abdominal and lie in scrotal sacs.
R – Scrotum acts as thermoregulator and keeps temperature lower by 2oC for normal sperm production .
a. A and R are true, R is the correct explanation of A
b. A and R are true, R is not the correct explanation of A
c. A is true, R is false d. Both A and R are false
Ans: A

2. A – Ovulation is the release of ovum from the Graafian follicle.
R – It occurs during the follicular phase of the menstrual cycle.
a. A and R are true, R is the correct explanation of A
b. A and R are true, R is not the correct explanation of A
c. A is true, R is false d. Both A and R are false
Ans: C

3. A – Head of the sperm consists of acrosome and mitochondria.
R – Acrosome contains spiral rows of mitochondria.
a. A and R are true, R is the correct explanation of A
b. A and R are true, R is not the correct explanation of A
c. A is true, R is false d. Both A and R are false
Ans: D

4. In which type of parthenogenesis are only males produced?
a) Arrhenotoky
b) Thelytoky
c) Amphitoky
d) Both a and b
Ans: A

5. Animals giving birth to young ones:
a) Oviparous
b) Oviviviparous
c) Viviparous
d) Both a and b
Ans: C

6. The foetal membrane that forms the basis of the umbilical cord is
a. Allantois b. Amnion
c. Chorion d. Yolk sac
Ans: A

7. The most important hormone in intiating and maintaining lactation after birth is
a. Oestrogen b. FSH
c. Prolactin d. Oxytocin
Ans: C

8. Mammalian egg is
a. Mesolecithal and non cleidoic
b. Microlecithal and non cleidoic
c. Alecithal and non cleidoic
d. Alecithal and cleidoic
Ans: C

9. The mode of reproduction in bacteria is by
a) Formation of gametes
b) Endospore formation
c) Conjugation
d) Zoospore formation
Ans: C

10. In which mode of reproduction variations are seen
a) Asexual
b) Parthenogenesis
c) Sexual
d) Both a and b
Ans: C

11 Colostrum is rich in
a. Ig E
b. Ig A
c. Ig D
d. Ig M
Ans: B

12.The Androgen Binding Protein (ABP) is produced by
a. Leydig cells
b. Hypothalamus
c. Sertoli cells
d. Pituitary gland
Ans: C

13.Which one of the following menstrual irregularities is correctly matched?
a. Menorrhagia   - excessive menstruation
b. Amenorrhoea   - absence of menstruation
c. Dysmenorrhoea - irregularity of menstruation
d. Oligomenorrhoea - painful menstruation
Ans: B

14. Find the wrongly matched pair
a. Bleeding phase - fall in oestrogen and progesterone
b. Follicular phase - rise in oestrogen
c. Luteal phase - rise in FSH level
d. Ovulatory phase - LH surge
Ans: C

15. The mature sperms are stored in the
a. Seminiferous tubules
b.Vas deferens
c. Epididymis
d. Seminal vesicle
Ans: C

16. The male homologue of the female clitoris is
a. Scrotum b. Penis
c. Urethra d.Testis
Ans: B

17. The site of embryo implantation is the
a. Uterus b. Peritoneal cavity
c. Vagina d. Fallopian tube
Ans: A

18. The milk secreted by the mammary glands soon after child birth is called
a. Mucous b. Colostrum c. Lactose d. Sucrose
Ans: B

19. The process which the sperm undergoes before penetrating the ovum is
a. Spermiation b. Cortical reaction
c. Spermiogenesis d. Capacitation
Ans: D

20. Painful menstruation is termed as
a. Dysmenorrhoea b. Menorrhagia
c. Amenorrhoea d. Oligomenorrhoea
Ans: A

21. The male sex hormone testosterone is secreted from
a. Sertoli cells
b. Leydig cell
c. Epididymis
d. Prostate gland
Ans: B

22. The glandular accessory organ which produces the largest proportion of semen is
a. Seminal vesicle b. Bulbourethral gland
c. Prostate gland d. Mucous gland
Ans: A

23. A contraceptive pill prevents ovulation by
(a) blocking fallopian tube
(b) inhibiting release of FSH and LH
(c) stimulating release of FSH and LH
(d) causing immediate degeneration of released ovum.
Ans: B

24. Read the given statements and select the correct option.
Statement 1: Diaphragms, cervical caps and vaults are made of rubber and are inserted into the female reproductive tract to cover the cervix before coitus.
Statement 2: They are chemical barriers of conception and are reusable.
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statement 1.
(c) Statement 1 is correct but statement 2 is incorrect.
(d)Both statements 1 and 2 are incorrect.
Ans: C

25. Select the incorrect action of hormonal contraceptive pills from the following
(a)Inhibition of spermatogenesis.
(b)Inhibition of ovulation.
(c) Changes in cervical mucus impairing its ability to allow passage and transport of sperms.
(d) Alteration in uterine endometrium to make it unsuitable for implantation.
Ans: A

26. Which one of the following groups includes sexually transmitted diseases caused by bacteria only?
(a) Syphilis, gonorrhoea and candidiasis
(b) Syphilis, chlamydiasis and gonorrhea
(c) Syphilis, gonorrhoea and trichomoniasis
(d) Syphilis, trichomoniasis and pediculosis
Ans: B

27. Which of the following is correct regarding HIV, hepatitis B, gonorrhoea and trichomoniasis?
(a) Gonorrhoea is a STD whereas others are not.
(b) Trichomoniasis is a viral disease whereas others are bacterial.
(c) HIV is a pathogen whereas others are diseases.
(d) Hepatitis B is eradicated completely whereas others are not.
Ans: C

28. Which of the following phenotypes in the progeny are possible from the parental combination AxB?
a) A and B only b) A,B and AB only c) AB only d) A,B,AB and O
Ans: D

29. Which of the following is true about Rh factor in the offspring of a parental combination DdXDd (both Rh positive)?
a) All will be Rh-positive b) Half will be Rh positive
c) About ¾ will be Rh negative d) About one fourth will be Rh negative
Ans: D

30. Haemophilia is more common in males because it is a
a) Recessive character carried by Y-chromosome
b) Dominant character carried by Y-chromosome
c) Dominant trait carried by X-chromosome
d) Recessive trait carried by X-chromosome
Ans: D

31. ABO blood group in man is controlled by
a)Multiple alleles b)Lethal genes c)Sex linked genes d)Y-linked genes
Ans: A

32. Which of the following is not correct?
a) Three or more alleles of a trait in the population are called multiple alleles.
b) A normal gene undergoes mutations to form many alleles
c) Multiple alleles map at different loci of a chromosome
d) A diploid organism has only two alleles out of many in the population
Ans: C

33. The _______deals with the control of several inherited human diseases especially inborn errors of metabolism
a) Euphenics b)Eugenics c)Euthenics d)All of these
Ans: A

34. In an extreme emergency condition, such as a serious accident, when there is great loss of blood and there is no time to analyse the blood group of the patient, which blood can be safely transferred to him/her?
a) ‘O’ and Rh negative b) ‘O’ and Rh positive
c)’B’ and Rh negative d) ‘AB’ and Rh positive
Ans: A

35. Klinefelters’ syndrome is characterized by a karyotype of
a) XYY
b) XO
c) XXX
d) XXY
Ans: D

36. Females with Turners’ syndrome have
a) Small uterus b) Rudimentary ovaries c) Underdeveloped breasts d) All of these
Ans: D

37.Pataus’ syndrome is also referred to as
a) 13-Trisomy b)18-Trisormy c)21-Trisormy d)None of these
Ans: A

38. Father of a child is colourblind and mother is carrier for colourblindness, the probability of the child being colourblind is
a) 25% b) 50% c) 100% d) 75%
Ans: B

39. A marriage between a colourblind man and a normal woman produces
a) All carrier daughters and normal sons b) 50% carrier daughters, 50% normal daughters
c) 50% colourblind sons, 50% normal sons d) All carrier offsprings
Ans: A

40. “Universal Donor” and “Universal Recipients” blood group are _____ and_______ respectively
a) AB, O b)O, AB c)A, B d)B, A
Ans: B

41. What can be the blood group of offspring when both parents have AB blood group?
a) AB only b) A, B and AB c) A, B, AB and O d) A and B only
Ans: B

42. XO type of sex determination and XY type of sex determination are examples of
a) Male heterogamety b) Female heterogamety c) Male homogamety   d) Both (b) and (c)
Ans: A

43. Mangolism is a genetic disorder which is caused by the presence of an extra chromosome number
a) 20 b) 21 c) 4 d) 23
Ans: B

44. ZW-ZZ system of sex determination occurs in
a) Fishes b)Reptiles c)Birds d)All of these
Ans: D

45. Who is the founder of Modern Eugenics movement?
a)Mendel b)Darwin c)Francis Galton d)Karl pearson
Ans: C

46.Improvement of human race by encouraging the healthy persons to marry early and produce large number of children is called
a) Positive eugenics b)Negative eugenics c) Positive euthenics d)Positive euphenics
Ans: A

47. Co-dominant blood group is
a) A b)AB c) B d)O
Ans: B

48. Which of the following is incorrect regarding ZW-ZZ type of sex determination?
a) It occurs in birds and some reptiles
b) Females are homogametic and males are heterogametic
c) Male produce two types of gametes
d) It occurs in gypsy moth
Ans: B

49. Hershey and Chase experiment with bacteriophage showed that
a) Protein gets into the bacterial cells b)DNA is the genetic material
c)DNA contains radioactive sulphur d)Viruses undergo transformation
Ans: B

50. DNA and RNA are similar with respect to
a)Thymine as a nitrogen base
b)A single-stranded helix shape
c) Nucleotide containing sugars, nitrogen bases and phosphates
d) The same sequence of nucleotides for the amino acid phenyl alanine
Ans: C

51.  A mRNA molecule is produced by
a)Replication b)Transcription c)Duplication d) Translation
Ans: B

52. Which of the following is the correct sequence of event with reference to the central dogma?
(a) Transcription, Translation, Replication (b) Transcription, Replication, Translation
(c) Duplication, Translation, Transcription (d) Replication, Transcription, Translation
Ans: D

53. The total number of nitrogenous bases in human genome is estimated to be about
a)3.5 million b)35000 c)35 million d)3.1 billion
Ans: D

54. Which of the following statements about DNA replication is not correct?
(a) Unwinding of DNA molecule occurs as hydrogen bonds break.
(b)  Replication occurs as each base is paired with another exactly like it.
(c) Process is known as semi conservative replication because one old strand is conserved in the new molecule.
(d) Complementary base pairs are held together with hydrogen bonds.
Ans: B

55. E. coli cell grown on 15N medium are transferred to 14N medium and allowed to grow for two generations. DNA extracted from these cells is ultracentrifuged in a cesium chloride density gradient. What density distribution of DNA would you expect in this experiment?
(a) One high and one low density band.
(b) One intermediate density band.
(c) One high and one intermediate density band.
(d) One low and one intermediate density band.
Ans: D

56. What is the basis for the difference in the synthesis of the leading and lagging strand of DNA molecules?
(a) Origin of replication occurs only at the 5' end of the molecules.
(b) DNA ligase works only in the 3' → 5' direction.
(c) DNA polymerase can join new nucleotides only to the 3' end of the growing stand.
(d) Helicases and single-strand binding proteins that work at the 5' end.
Ans: C

57. Meselson and Stahl’s experiment proved
(a)Transduction
(b) Transformation
(c) DNA is the genetic material
(d) Semi-conservative nature of DNA replication
Ans: D

58. Which of the following statements is not true about DNA replication in eukaryotes?
(a) Replication begins at a single origin of replication.
(b) Replication is bidirectional from the origins.
(c) Replication occurs at about 1 million base pairs per minute.
(d) There are numerous different bacterial chromosomes, with replication occurring in each at the same time.
Ans: D

59. An operon is a:
(a) Protein that suppresses gene expression
(b) Protein that accelerates gene expression
(c) Cluster of structural genes with related function
(d) Gene that switched other genes on or off
Ans: C

60. The first codon to be deciphered was __________ which codes for ________.
(a) AAA, proline (b) GGG, alanine (c) UUU, Phenylalanine (d)TTT, arginine
Ans: C

61. When lactose is present in the culture medium:
(a) Transcription of lac y, lac z, lac a genes occurs.
(b) Repressor is unable to bind to the operator.
(c) Repressor is able to bind to the operator.
(d) Both (a) and (b) are correct.
Ans: D

62) The age of fossils can be determined by
a)electron microscope b)weighing the fossils
c)carbon dating d)analysis of bones
Ans: C

63. The phenomenon of “ Industrial Melanism” demonstrates
a)Natural selection b)induced mutation
c)reproductive isolation d)geographical isolation
Ans: A

64. Fossils are generally found in
a)igneous rocks b) metamorphic rocks c)volcanic rocks d) sedimentary rocks
Ans: D

65. The first life on earth originated
a)in air b)on land c)in water   d) on mountain
Ans: C

66. Which of the following was the contribution of Hugo de Vries?
a)Theory of mutation b)Theory of natural Selection
c) Theory of inheritance of acquired characters d)Germplasm theory
Ans: A

67. Darwin’s finches are an excellent example of
a)connecting links b) seasonal migration c)adaptive radiation d) parasitism
Ans: C

68. Who proposed the Germplasm theory?
a) Darwin b) August Weismann c)Lamarck d) Alfred Wallace
Ans: B

69. Which period was called “Age of fishes”?
a) Permian b) Triassic   c) Devonian d) Ordovician
Ans: C

70. The wings of birds and butterflies is an example of
a)Adaptive radiation b)convergent evolution c)divergent evolution d)variation
Ans: B

71. Who published the book “Origin of species by Natural Selection” in 1859?
a)Charles Darwin b)Lamarck c)Weismann d)Hugo de Vries
Ans: A

72. Modern man belongs to which period?
a) Quaternary b) Cretaceous   c) Silurian d) Cambrian
Ans: A

73. The golden age of reptiles was
a) Mesozoic era b) Cenozoic era c) Paleozoic era d) Proterozoic era
Ans: A

74. The Neanderthal man had the brain capacity of
a ) 650 – 800cc b) 1200cc   c) 900cc d) 1400cc
Ans: D

75. Evolutionary history of an organism is called
a)ancestry b)ontogeny c)phylogeny d)paleontology
Ans: C

76. Cirrhosis of liver is caused by chronic intake of -----
a)Opium b)Alcohol c)Tobacco d)Cocaine
Ans: B

77. Poliomyelitis which causes infantile paralysis enters the body through……….
a) Skin b) Mouth and nose c) Ears d) Eyes
Ans: D

78. Amphetamines are stimulants of the CNS, whereas barbiturates are ---
a)CNS stimulant b) both a and b c)hallucinogenic d) CNS depressants
Ans: D

79. The sporozoite of the malarial parasite is present in ---
a) saliva of infected female Anopheles mosquito. b) RBC of human suffering from malaria.
c)Spleen of infected humans. d)Gut of female Anopheles mosquito.
Ans: A

80. Marijuana is extracted from
a) Dried leaves and flowers of hemp plant. b) Ergot fungus
c) Roots of hemp plant d) Cocoa plant
Ans: A

81. Choose the correctly match pair.
a) Amphetamines - Stimulant b) LSD - Narcotic
c) Heroin - Psychotropic d) Benzodiazepine - Pain killer
Ans: A

82. Which of the following disease is spread through droplet nuclei?
a) Tularemia b)Listeriosis c) Chicken pox d)Mumps
Ans: C

83. Exo-erythrocytic schizogony of Plasmodium takes place in ------
a) RBC b)Leucocytes c) Stomach d) Liver
Ans: D

84. The Athlete’s foot disease in human is caused by------
a)Bacteria b)Fungi c)Virus d)Protozoan
Ans: B

85. Haemozoin is
a)A precursor of haemoglobin. b)A toxin from Streptococcus.
c)A toxin from Plasmodium species. d)A toxin from Haemophilus species.
Ans: C

86. Malaria caused by Plasmodium is transmitted through-------
a)Air b)Contact c)Fleas on food d)Mosquito bites
Ans: D

87. A 30 year old woman has bleedy diarrhoea for the past 14 hours, which one of the following organisms is likely to cause this illness?
a) Streptococcus pyogens b) Clostridium difficile
c) Shigella dysenteriae d) Salmonella enteritidis
Ans: C

88. The sporozoites of Plasmodium vivax are formed from -----------
a) Gametocytes b) Sporoblasts c) Oocysts d)Spores
Ans: C

89. The drug synthesised from Datura is
a)Hallucinogen b) Depressant c)Stimulant d)Pain killer
Ans: A

90. In agglutination and precipitation reactions, the antigen is a ______________ and ____________ respectively
(A) Whole cell/soluble molecule (B) Soluble molecule/whole cell (C) Bacterium/virus (D) Protein/Antibody
Ans: A

91. AIDS virus has
(A) Single stranded RNA (B) Double stranded RNA (C) Single stranded DNA (D) Double stranded DNA
Ans: A

92. All are peripheral lymphoid organs except
(A) Lymph nodes (B) Spleen (C) Mucosa associated lymphoid tissue (D) Thymus
Ans: D

93. Which is not a macrophage?
(A)Monocyte (B)Microglia (C)Kupffer cell (D)Lymphocyte
Ans: D

94. B cells that produce and release large amounts of antibody are called
(A) Memory cells (B) Basophils (C) Plasma cells (D) killer cells
Ans: C

95. Spread of cancerous cells to distant sites is termed as
(A) Metastasis (B) Oncogenes (C) Proto-oncogenes (D) Malignant neoplasm
Ans: A

96. True about interferon is that
(A) It is synthetic antiviral agent (B) It inhibits viral replication in cells
(C) It is specific for a particular virus (D) It causes infection
Ans: A

97. Vimal is injured and got swelling. The swelling is due to the infection of tissue is an example of
(A) Mechanical barrier (B) Physiological barrier (C) Phagocytosis (D) Inflammation
Ans: D

98. Anaphylactic shock is due to
(A) Allergic reaction (B) Secretion of toxins (C) Secretion of histamines (D) All the above
Ans: A

99. Cell mediated immunity is carried out by………….. while humoral immunity is mainly carried out by
(A) B cells/T cells (B) Epitopes/antigens (C) T cells/B cells (D) antibodies/antigens
Ans: C

100. Paratope is an
(A) Antibody binding site on variable regions (B) Antibody binding site on heavy regions
(C) Antigen binding site on variable regions (D) Antigen binding site on heavy regions
Ans: C

ZOOLOGY

UPSC CSE Mains Zoology Syllabus

UPSC Study Materials​MCQs for Competitive Examinations

UPSC Study Materials
MCQs for Competitive Examinations