Civil Services Main Examination 2020 Botany (Optional) Paper II


Section ‘A’

1.Write short notes on/Answer the following:10×5=50

(a) Applications of probes in Southern blotting. 10
(b) Nuclear pore complex and its functions.10
(c) Structure and behaviour of B-chromosomes.10
(d) Why are overlapping genes important? Discuss.10


2.(a) Discuss major steps in signal transduction. 15
(b) Describe the significance and uses of the following:8+7=15

(i) Male sterility
(ii) Polyploidy in plant breeding.
(c)Transgenic technology is a breakthrough innovation. Justify with examples. 20


3.(a) Briefly describe two theories of Chiasma formation. Discuss whether Chiasmata are the cause or consequence of crossing-over.8+7=15
(b) What is Antisense RNA? Explain its applications and describe the catalytic activity of RNA. 5+5+5=15
(c) Does Z-DNA play a regulatory role? Discuss critically. 20


4.(a) Explain the mode of biogenesis peroxisomes and discuss their functions.5+10=15
(b) Name the phyto-geographical regions of India. Which are the dominant flora of the region representing the west coast of India from Kanyakumari to Satpura ranges in Gujarat? 5+10=15
(c)"Cell cycle is an ordered series of events leading to cell replication." Discuss.20


Section ‘B’


5.Write short notes on/Answer the following:10×5=50

(a) Climacteric fruits and their advantage to fruit growers. 5+5=10
(b) Metabolic energy requirement for uptake of sucrose in apoplastic pathway.10
(c) Cyanide-resistant respiration in plants.10
(d) Can Intellectual Property Rights protect and safeguard farmers' rights and interests? 10
(e) What are the causes of the rise in mean atmospheric temperature and how will it influence the climate of a region? 5+5=10


6.(a) Carboxylation and oxygenation compete to decrease the efficiency of photosynthesis. Discuss.15
(b) What is drought escape? Discuss different strategies adopted by plants for drought resistance.5+10=15
(c) What is Clock hypothesis? Justify the importance of main photoreceptor and photoperiodic induction in photoperiodism. 5+15=20


7.(a) How can the two laws of thermodynamics be combined to determine spontaneity of a reaction? Also derive a relationship between free energy exchange and equilibrium constant.7+8=15
(b) What is bioremediation? How can plants be used to detoxify the heavy metal containing industrial effluents? 5+10=15
(c) What is the importance of fatty acid synthase complex? Discuss the growth of fatty acyl chain through priming and elongation phases 5+15=20


8.(a) How is solar energy trapped, fixed and transformed in an aquatic food chain? 5+5+5=15
(b) How do microbes help in chemical recycling in nature for a stable community climax? 15
(c) Eco-development sequence proceeds from a barren land to a climax and finally ends in desert. Explain critically. 10×10=20