(Download) UPSC MAIN EXAM : 2026 BOTANY (Paper-2)

(Download) CS (MAIN) EXAM:2026 Botany (Paper II)

• Exam Name: CS (MAIN) EXAM:2026 Botany (Paper II)

• Marks: 250

• Time Allowed : Three Hours

खण्ड - A / SECTION — A 

1. Answer the following questions in about 150 words each : 10×5=50 

• (a) Frame Shift mutation

• (b) Lampbrush chromosome and its significance

• (c) Reporter genes

• (d) Cell signalling and Cell receptors

• (e) DNA finger printing

2.

• (a) Give a detailed account on sex linked inheritance? (20)

• (b) Explain the structural variations of chromosomes and their significance. (15)

• (c) Describe the role of Biochemical and Molecular basis of Mutation. (15)

3.

(a)

• (i) Write in detail the chemical composition of microtubules. (10)

• (ii) Elaborate the functions of cytoplasmic microtubules. (10)

(b) Explain the different means of passive transport across the plasma membrane. (15)

(c)

• (i) Elaborate on the significance of molecular markers. (8)

• (ii) Explain the significance of polyploidy in Agriculture. (7)

4.

• (a) Discuss on the tools and techniques involved in PCR and FISH. (20)

• (b) Explain the causes of Heterosis and its impact in Agriculture. (15)

• (c) Describe the various evidences supporting organic evolution. (15)

खण्ड - B / SECTION —— B

5. Answer the following questions in about 150 words each :10 × 5 = 50 

• (a) Munch hypothesis

• (b) Correlation and Regression

• (c) Heat Shock Proteins (HSP's)

• (d) Biogeochemical cycle

• (e) Regulation of NIF genes

6.

• (a)

  • (i) Explain the significance of Nod factors and the process of root nodule formation. (10)

  • (ii) Describe the process of amino acid biosynthesis in nitrogen metabolism. (10)

• (b) Differentiate between photophosphorylation and oxidative phosphorylation. (15)

• (c) Discuss the biochemical and physiological changes during the process of fruit ripening. (15)

7.

(a)

• (i) Explain the factors affecting enzyme activity. (10)

• (ii) Describe the mechanism of enzyme action. (10)

(b) Explain the following:

• (i) Acid rain (5)

• (ii) Biocide as pollutant (5)

• (iii) Photochemical smog (5)

(c)

• (i) Describe seed dormancy and explain how is it getting regulated? (8)

• (ii) Explain biochemical changes taking place during the seed germination. (7)

8.

(a)

• (i) What is the basic concept of phytogeography? (5)

• (ii) Give a detailed account on various phytogeographical regions of India. (15)

• (b) Give an account on farmers rights and intellectual property rights. (15)

• (c) Discuss on the present status of forest resources of India. Give the factors responsible for deforestation. (15)

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