WEST BENGAL CIVIL SERVICE
EXAMINATION - 2007
Zoology Paper-II
Time Allowed-3 Hours Full Marks-100
Group - A
(Answer any three questions.)
1. (a) Describe the nucleosome model of chromosome structure. 10
(b) Give an account of various phases of cell cycle. 5
(c) Draw the ultrastructure of a mitochondria. 3
(d) What is SEM ? 2
2. (a) What is spermiogcnesis ? Describe the process of spermiogenesis. 2+4
(b) Distinguish between mesolecithal and megalecithal eggs; give one example each. What is a telolecithal egg ? 4+1+2
(c) Give an account of hypoblast formation in chick embryo. 4
(d) What do you mean by capacitation ? 3
3. (a) What is the primary structure of a protein ? 2
(b) What are conjugated proteins ? Give two examples. 2+1
(c) Give examples of water soluble vitamins. 2
(d) What do you mean by a reducing sugar ? 2
(e) What is epimerism ? Give an example. 2+1
(f) Distinguish between gluconeogenesis and glycogenosis. 2
(g) What is facultative reabsoiption of water ? Where does it take place in our body and how does it take place ? 2+1+3
4. (a) What is binomial nomenclature ? 2
(b) What is a living fossil ? 2
(c) Distinguish between sympatric and allopatric speciation. 5
(d) What is Hardy-Weinbcrg equilibrium ? 3
(e) What is cladogenesis ? 2
(f) How do you define a race ? 2
(g) Distinguish between a sibling species and a sub-species. 4
5. (a) What is anticodon ? 3
(b) What are Okazaki fragments ? 3
(c) Name the sugar, pyrimidine and purine bases found in DNA and RNA. 3
(d) State the functions of DNA ligase. 2
(e) What is synaptonemal complex ? 3
(f) What is transcription ? 2
(g) Describe the structure of t-RNA. 4
6. Write short notes :
(a) Significance of meiosis. 3
(b) Endoplasmic reticulum. 5
(c) Fertilization cone. 4
(d) Gap junctions. 4
(e) Cholecalciferol. 4
Group—B
Answer any two of the following questions.
7. (a) Give Michaelis-Menten equation (derivation not needed). What is Km ? 1+2
(b) Explain "Induced-fit Model" of enzyme action. 5
(c) Define isozymes. 2
(d) What is heteroglycan ? 2
(e) What is iodine number ? 2
(f) Which visual pigment is responsible for dim-light vision ? Give the chemical composition of this pigment. In which part of the eye is this pigment found ? How visual impulse is formed ? 1+1+1+3
8. (a) What is a polocyte or a polar body ? What is its significance in orogenesis ? 2+2
(b) Discuss in brief the induction phenomenon during the development of eye in vertebrates. 5
(c) What is the significance of primitive streak formation during gastrulation in chick ? 4
(d) State the significance of blustocoel formation prior to gastrulation. 2
(e) What is ultrafiltration ? In which part of our body ultrafiltration takes place ? 11/2+11/2
(f) What is renal threshold ? 2
9. (a) Distinguish between :
(i) Enzyme and ribozyme. 4
(ii) Bottle neck effect and founder effect. 4
(b) Explain punctuated equilibrium. 4
(c) Describe the experiment of Urey and Miller in connection with the origin of life on earth. 4
(d) How angiotensin II is formed from angiotensinogen ? State the functions of angiotensin II. 2+2
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