WEST BENGAL CIVIL SERVICE
EXAMINATION - 2001
Time Allowed-3 Hours Full Marks-100
Group - A
(Answer any three questions.)
1. How would you distinguish between a male and a female Ascaris ? State briefly the life-cycle of Ascaris lumbricoided. Add a note on its pathogenicity and control. 5+10+3+2 = 20
2. What is reproduction ? State different methods of reproduction in the following Protozoa.
(a) Amoeba Proteus
(b) Euglena Viridis
(c) Plasmodium Vivax
(d) Paramoecium. Caudatum 4+4 X 4 = 20
3. What is ciliary mode of feeding ? Give an account of its mechanism in lower chordates. Comment on its evoluitonarv significance. 2+15+3 = 20
4. Distinguish between neotetvy and paedogenesis. Describe the phenomenon of neotenv in Amphobia with suitable examples. State the hormonal control of Neoteny. 4+10+6 = 20
5. Write short notes on any four of the following :-
(a) Ultrastructure of Cilia and flagella
(b) Coral and coral-reef formation,
(c) Torsion and detorsiort in Gastropoda,
(e) Exoskeletal structures in Pigeon.
(f) Ruminant stomach.
(g) Affinities of etenophora.
(h) biling Mechanism in Snakes. 5x4 = 20
Group - B
Answer any two questions.
6. What is ecosystem ? Mention the main structural and functional components of an ecosystem. What is food-chain ? Explain with suitable examples the Grazing and Detritus food-chain in the ecosystem. Define ecotone and edge-effect. 2 + 4 + 2 + 8 + 4 = 20
7. Define pollution. Classify the pollutants responsible for Air-pollution. Discuss briefly the various causes of Air-pollution. State the effective measures for controlling air-pollution. 2 + 4 + 8 + 6 = 20
8. (a) What is silk ? Mention its composition . 2 + 3
(b) Discuss the causative agents, symptoms and control, measures of the diseases of silk worm larvae. 10
(c) Comment on the application of bio-technology in the improvement of silk worm strains. 5
9. Gvie brief idea about any four of the following:
(a) Circadian rhythm,
(b) Role of hormone in animal behaviour,
(c) Method of polyculture in India ,
(d) Major paddy pests .
(e) Chi-square and 't' test,
(f) Prospect of Pearl Culture in India ,
(g) Bio-diversity ,
(h) Ozone -hole. 5 x 4 = 20