IAS Mains Zoology Paper-I 2011

Time Allowed: Three Hours

Maximum Marks: 300

Instructions

Each question is printed both in Hindi and in English.

Answer must be written in the medium specified in the Admission Certificate issued to you, which must be stated clearly on the cover of the answer-book in the space provided for the purpose. No marks will be given for the answer written in a medium other than that specified in the Admission Certificate.

Candidates should attempt Question Nos. 1 and 5 which are compulsory, and any three of the remaining questions selecting at least one question from each Section.

The number of marks carried by each question is indicated at the end of the question.

Illustrate your answer with suitable diagrams, wherever necessary.

Section-A

  1. Answer concisely the following in about 150 words each: 15 × 4 = 60

    1. What was the need to create Parazoa against Porifera when the latter existed?

    2. Provide diagrammatic representation of the stages of conjugation in Paramecium and comment on its autogamy.

    3. Compare the skill of Rhynchocephalia with that of Crocodilia.

    4. Draw a well-labelled schematic diagram of the feeding current through the gut of Branchiostoma, and comment on the mechanism of feeding and digestion.

  2. Answer any two of the following: 30 × 2 = 60

    1. Describe the great departures shown by parasitic forms from the diagnostic features of fee living forms among Copepoda.

    2. Describe the structures and function of water-vascular system in echinoderms.

    3. Give the salient features of Apterygota and Pterygota.

  3. Answer the following questions

    1. What is mutable connective tissue? Describe the various functions it serves and the mechanism of its working. 30

    2. With the help of a well-labelled diagram (ventral aspect), describe the heart of rabbit showing major blood vessels. Add a note on the mechanism of circulation through the heart. 30

  4. Answer the following questions

    1. Differentiate between open and closed circulatory systems. 30

    2. Define Migration Add a detailed account of migration. In fishes with relevant examples. 30

Section-B

  1. Answer, in brief, the following in about 150 words each: 15X4 = 60

    1. Draw a flow diagram of nitrogen cycle, and give accounts of nitrogen fixation, nitrification and denitrification.

    2. Give the mechanism of ozone degradation by chlorofluorocarbons.

    3. What is crypsis? Discuss the significance of crypsis in different animals.

    4. Discuss with suitable examples the importance of the measure of central tendency and dispersion.

  2. Answer any two of the following: 30X2 = 60

    1. “A population is a self-regulating system” (Wynne Edwards.) Explain.

    2. Define memory, and discuss how short-and long-term memory are stored.

    3. Distinguish between in situ and ex situ conservation of animals. Provide suitable examples.

  3. Answer the following questions

    1. What is chi-square (? 2) test? Add a detailed account on the computation of chi-square for tests of independence, homogeneity and goodness of fit, using biological data. 30

    2. Discuss the effect of hormones on sexual, aggressive and maternal behavior. 30

  4. Answer the following questions

    1. Discuss briefly theoretical basis of spectrophotometry with reference to the Beer-Lambert law. Write an account of the instruction, maintenance and application of spectrophotometer. 30

    2. Discuss the theoretical basis of spectrophotometry with reference to the Beer-Lambert law. Write an account of the instrumentation, maintenance and application of spectrophotometer. 30