WEST BENGAL CIVIL SERVICE
EXAMINATION - 2008
Zoology Paper-II
Time Allowed-3 Hours Full Marks-100
Group - A
(Answer any three questions.)
1. (a) Describe the ultra structures of Golgi bodies. 8
(b) Write briefly how Golgi bodies are formed. 4
(c) Enumerate principal functions of the Golgi bodies. 5
(d) Name three enzymes found in outer membrane, inner membrane and the matrix of mitochondria. Comment on their functions. 3
2. (a) Name and describe the molecular changes exhibited by ejaculated sperms favouring fertilization. 8
(b) Give diagram and explain the structure of zona proteins. 5
(c) Write short notes on :
(i) Role qf yolk in cleavage 31/2
(ii) Ultra structure of sperm 31/2
3. (a) Explain with a diagram the nucleosome model. 6
(b) How from Klinefelter and Turner karyotypes and their corresponding sexual phenotypes, you may conclude that Y chromosome determines maleness in human ? 4
(c) What is specialised transduction ? Explain with example. 5
(d) State the role of RNA polymerase-II in transcription. 5
4. Write notes on any five :
(a) Southern blot technique
(b) 'C value paradox
(c) X ist gene
(d) YAC
(e) Sex-influenced traits
(f) Shine-Dalgarno Sequence
(g) Okazaki fragments. 4x5
5. (a) Explain Hardy-Weinburg equilibrium. 2
(b) Cystic fibrosis is an autosomal recessive disorder, in certain population in North Europe, this disorder show an incidence of 1/2500. What proportion of individuals in this population are carriers for this disease ? Justify your calculations. 6
(c) What do you mean by "stabilizing selection" and "directional selection" ? 4
(d) Point out the phyletic gradualistic trends in the equine evolution. 8
Group-B
Answer any two questions.
6. Write notes on any five :
(a) Zoological nomenclature
(b) Lectotype and syntype
(c) 'OTU'
(d) [tex]\alpha[/tex], [tex]\beta[/tex], [tex]\gamma[/tex]-taxonomy
(e) Category
(f) Cryptic species
(g) Biological species concept. 4x5
7. (a) What is "All-or-Nothing" principle ? 2
(b) Explain all the factors that determine the resting membrane potential of nerve fibres. 4
(c) What are the successive stages of the action potential which we find in a nerve fibre, during transmission of signals ? Explain with diagram. 8
(d) What is gluconeogenesis ? Schematically describe this pathway. 6
8. (a) Discuss briefly the primary, secondary, tertiary and quarternary structure of protein. 8
(b) What is allosteric modulation. 2
(c) What do you know about competitive, noncompetitive and uncompetitive inhibition of enzyme ? 6
(d) What is xerophthalmia and beriberi. 4
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