W.B Civil Service Examination (Main)- 2001
(Optional Papers)
Botany Paper-II
Time Allowed-3 Hours Full Marks-100
Group - A
Answer any three questions
I. (a) What are polygenes or nultiple factors ? Give example.
(b) Explain why do you expect differences among cells arising from meiosis and not from mitosis,
(c) What are the genetic consequences of inversion ?
(d) How can you distinguish between haploidy and monoploidy ? 2
(e) Explain briefly the general properties of genetic code. 6
(f) Schematically represent the reverse flow of transcriptional information. 2
2. (a) Explain why do you consider mitochondria and chloriplasts as semi autonomous organelles 3
(b) Describe one experiment demonstrating DNA as a genetic material. Characterise the different forms of DNA. 4+3
(c) What are histones ? How do the different histone molecules arrange specially in a nucleosome ? 1+3
(d) What are the achievements of gene transfer technology ? 4
(e) What is genomic library ? 2
3. (a) What role can mutations play in evolution ? 3
(b) What is Neo-Darwinism ? 3
(c) What is base substitution ? Give example. 3
(d) How enzymatic reactions are influenced by substrate concentration ? What is enzyme inhibition ? 6+2
(e) How do Gibberllins induce seed germination ? 3
4. (a) What is oxidative phosphorylation ? 3
(b) Give a balance sheet for yield of ATP during oxidative phosphorylation in mitochondria.
(c) Indicate when the RQ values become Zero, less than unity and infinity. 3
(d) Name two non symbiotic Nitrogen fixers. 2
(e) Characterise the nitrogenase enzyme complex. 4
(f) Why Boron is considered as an important micronutrient in plants ? 4
5. (a) How does Osmosis play significant role in plant life ? 3
(b) What are antitranspirants ? What essential features would you suggest for an ideal antitranspirant ? 1+2
(c) Explain the Emerson enhancement effect. 4
(d) Briefly describe the anatomical characteristics of C4 plants. 3
(e) State the biosynthetic pathway of ethylene. 4
(f) Explain the phenomenon of vernalization. 3
Group-B
Answer any two questions.
6. (a) How do the biotic factors influence vegetation of a particular area ? 6
(b) Describe briefly the structural adaptive features in
(i) epiphytes (ii) desert plants (iii) mangroves. 3+3+3
(c) Compare the flora of eastern Himalaya with that of western Himalaya. 3
(d) What is a climax forest ? 2
7. (a) Give the botanical names with their respective families, parts used and economic importance of the following :
(i) Sunn hemp (ii) Teak (iii) Kurchi (iv) Fan palm. 4 x 4
(b) Mention the ideal climatic and edaphic conditions for tea or jute cultivation.
8. Write shor notes on any five and their significance.
(a) Green house gases and their significance.
(b) The Quadrat method of studying vegetation.
(c) Biopollutants.
(d) Factors responsible for endemism.
(e) Spice yieldig plants of India.
(f) Silviculture. 4 x 5
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