UPSC Civil Services Mains Exam: Zoology Optional 2018 Paper-II
Baljit Dhaka
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UPSC Civil Services Mains Exam: Zoology Optional 2018 Paper-II

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UPSC Civil Services Mains Exam: Zoology Optional 2018 Paper-II

Marks-250                                                                                                                                        Time: Three Hours

Question Paper Specific Instructions:

Please read each of the following instructions carefully before attempting questions.

  • There are EIGHT questions divided into two sections.
  • A candidate has to attempt FIVE questions in all.
  • Questions no 1 and 5 are compulsory and out of the remaining, THREE are to be attempted choosing at least ONE from each section.
  • The number of marks carried by a question /part is indicated against it.
  • Word limit in questions, wherever specified should be adhered to.
  • Attempts of questions shall be counted in chronological order. Unless struck off, attempt of a question shall be counted even if attempted partly. Any page or portion of the page left blank in the answer book must be clearly struck off.


Q1.(a) What are Euchromatin and Heterochromatin? Explain the events of Heterochromatin formation. 10 marks

(b) What are fossils? Describe the process of fossil formation and give two methods of determining the age of fossils. 10 marks

(c) Describe the traditional methods of classification of animals. 10 marks

(d) Explain the use of VNTRs in DNA fingerprinting in paternity tests. 10 marks

(e) Explain the origin and functions of lysosomes with emphasis on different enzymes. 10 marks

Q2.(a) Describe the role of protein kinases in the regulation of cell cycle. Add a note on the importance of checkpoints. 20 marks

(b) Comment on the following human genetic disorders: 15 marks
(i) Down Syndrome
(ii) Klinefelter's Syndrome
(iii) Sickle Cell Anaemia

(c) With suitable examples, describe how adaptive radiation helps in the evolution of terrestrial and aquatic animal groups. 15 marks

Q3.(a) Describe the structure of plasma membrane according to the fluid mosaic model with emphasis on the role of lipid molecules in maintaining the fluidity of the membrane. 20 marks

(b) What are micro, macro and mega evolutions? Explain the terms with suitable examples. 15 marks

(c) Explain the distinctive features of plasmid and cosmid vectors used in recombinant DNA technology. 15 marks

Q4.(a) Define Isolation. Explain in detail the pre-mating and post-mating isolating mechanisms. 20 marks

(b) Explain in detail about the events involved in the transformation of spermatid into sperm. Comment on why you consider these changes as essential. 15 marks

(c) Explain the phenomenon of X-linked inheritance in Drosophila. 15 marks


Q5.(a) Describe the role of Acetylcholine in neuromuscular transmission. 10 marks

(b) Describe the role of fertilizin and anti-fertilizin interactions during fertilization. 10 marks

(c) Define Muscle twitch and explain the features of Summation and Tetanus. 10 marks

(d) Explain the role of pancreatic enzymes indigestion. 10 marks

(e) Who proposed Binomial Nomenclature? Describe the rules of Zoological Nomenclature. 10 marks

Q6.(a) Describe the role of pituitary and gonadal hormones on puberty and regulation of menstrual cycle. 20 marks

(b) Describe the role of visual pigments in daylight and night vision. 15 marks

(c) With particular reference to Gradient theory, describe how polarity is established during embryonic development. Comment on its significance. 15 marks

Q7. (a) Describe in detail about the respiratory chain or electron transport during oxidative phosphorylation in Mitochondria. 20 marks

(b) Give an account of the impact of drugs on teratogenesis. 15 marks

(c) What are fate maps? Describe the methods of fate maps construction with reference to frog or chick. 15 marks

Q8.(a) Describe the role of Calcitonin, Parathormone and Vitamin D, in calcium metabolism. 20 marks

(b) Describe in detail about the structure and function of Nephron and explain fluid balance regulation through Renin-Angiotensin-Aldosterone systems. 15 marks

(c) Give an account of the morphological and histological types of placenta Add a note on the physiological function of mammalian placenta. 15 marks

UPSC Civil Services Mains Exam: Psychology Optional 2018 Paper-II

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