W.B Civil Service Examination (Main)- 2007
(Optional Papers)
Botany Paper-II
Time Allowed-3 Hours Full Marks-100
Group - A
Answer any three questions
1. Attempt any five : 4 x 5
(a) Distinguish between auto and allopolyploidy. Which type of polyploidy would favour the formation of bivalents in meiosis ?
(b) Name and explain in brief the role of some key proteins in DNA replication.
(c) Distinguish between a nucleosome and a nucleosome core particle. What protein molecules does each contain and what length of DNA ?
(d) Distinguish between a paracentric and pericentric inversion. What types of chromosomal abnormalities in meiosis are associated with each of these ? How are those abnormalities related to crossing over ?
(e) What is a primary transcript ? How does a primary transcript in eukaryotes differ from that in prokaryotes ?
(f) Write a genetic evidence for triplet nature of genetic code.
2. Attempt any five : 4 x 5
(a) What do you mean by [tex]\alpha[/tex]-helix and [tex]\beta[/tex]-pleated sheet ? Name the different bonds needed to form the tertiary structure of protein.
(b) What is oxidative decarboxylation ? Mention one such reaction in T.C.A. cycle.
(c) Distinguish between action spectra and absorption spectra and represent graphically these two spectra with a pigment.
(d) Why is hexose monophosphate shunt pathway called oxidative pentose phosphate pathway ? What is the significance of this pathway ?
(e) What are cytokinins ? Explain the role of cytokinins in leaf senescence.
(f) What do you mean by CAM plants? Mention the physiological significance of CAM plants.
3. Attempt any five : 4 x 5
(a) State the reasons for global warming.
(b) Mention in brief the adoptive features of mangrove vegetation in West Bengal.
(c) What is Red Data Book ? What do you mean by 'hot spot region' ? Name two endangered plants.
(d) Describe if brief the different stages of plant succession in a hydrosere.
(e) Discuss the special structural adaptive features of
(i) an epiphytic orchid, (ii) a typical cactus.
(f) What is meant by a plant community ? How does it originate in a particular area ?
4. Attempt any five : 4 x 5
(a) Give the scientific names and families of two fibre yielding plants and state the uses of the mentioned plant sp.
(b) Write the medicinal importance of (i) Azadirachta indica, (ii) Atropa belladonna.
(c) Give the scientific name of the plant, family and purpose of use of the following : Teak, Ginger, Sarpagandha, Coconut.
(d) Give the scientific name of the plant, family and use of the following alkaloids -
(i) quinine, (ii) chiraten, (iii) curcumin, (iv) kurchin.
(e) What is the scientific name of 'bread wheat'? Give a brief idea about origin of bread wheat.
(f) Distinguish between mean, median and mode.
5. Attempt any five : 4 x 5
(a) Distinguish between C3 and C4 plants regarding the photosynthetic carboxylative reaction. Why are C4 plant considered to be photosynthetically more efficient than C3 plants ?
(b) Explain the mechanism of 'charging of t-RNA'.
(c) What do you mean by positive and negative regulation of transcription ? Give an example of positive regulation.
(d) What is a telomere ? How are telomeres elongated in each cycle ?
(e) Describe the type of reaction catalyzed by the following enzymes. Give an example of complete reaction is each case: (i) a kinase, (ii) an isomerase.
(f) What is photorespiration ? Name the organelles involved in photorespiration. Why is photorespiration not an entirely useless process ?
Group-B
Answer any two questions.
6. Attempt any five : 4 x 5
(a) 'How the haploids can be raised in vitro ?
(b) 'What is fusogen ? Name a fusogen. Write the protocol for protoplast culture.
(c) What is heterosis ? Discuss the dominance theory of heterosis.
(d) What is artificial seed ? State the significance for developing artificial seed.
(e) Mention the steps to raise C-DNA library.
(f) What is DNA finger printing ? What is the utility of this technique ?
7. Attempt any five : 4 x 5
(a) Name two aromatic and two sulphur containing amino acids. How are two amino acids joined during protein synthesis ?
(b) Discuss the role of K+ in opening and closing of stomata. Mention the name of a hormone which also plays a role in the process.
(c) What is pure line selection ? Mention its advantages.
(d) Define microclimate. Explain how does microclimate regulate the growth of living organisms.
(e) What is facilitated diffusion ? How does it differ from simple diffusion? Explain the process of facilitated diffusion.
(f) Briefly describe two methods of gene transfer in plants.
8. Attempt, any five : 4 x 5
(a) What is leg-haemoglobin ? What role does it play in nitrogen fixation ?
(b) What do you mean by substrate-level-phosphorylation ? How many ATP molecules are formed by substrate-level phosphorylation in glycolysis ? Write the specific reaction of glycolysis which is oxidative in nature.
(c) Define energy in an ecosystem. Discuss the pattern of energy flow in an ecosystem.
(d) What do you mean by bioindicators ? Write with examples how bioindicators are used to indicate environmental conditions.
(e) What are the objectives of conservation of nature and natural resources ? Explain the impact of deforestation on ecosystem.
(f) What are multiple alleles? Explain the phenomenon using a suitable example.
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