IAS UPSC (CSE) Mains 2002: Botany

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  1. Answer any three of the following in not more than 200 words each: 20 × 3 = 60

    1. Recent studies reveal that mesosomes are artifacts and not true structures. Discuss.

    2. What is heterospory? Discuss seed habit in ptendophytes giving suitable examples.

    3. Describe the ultra structure and role of heterocyst in blue-green algae.

    4. Describe the economic importance of bryophytes giving suitable examples.

  2. Answer the following questions

    1. What are biosensors? Describe the applications of microbiology in industry.

    2. What are mycorrhizae? Describe economic potential of mycorrhizal fungi in agriculture and forestry. 30 × 2 = 60

  3. What is apogamy? Describe the structure and arrangement of sex organs in bryophytes with the help of suitable diagrams. 60

  4. Answer the following questions

    1. Differentiate between hybrids and cybrids. How are cybrids obtained?

    2. What is callus? Describe the process of differentiation from callus. 30 × 2 = 60


  1. Answer any three of the following in not more than 200 words each: 20 × 3 = 60

    1. What are progymnosperms? Describe with examples their morphology.

    2. Differentiate between velamen and exodermises.

    3. What is Krantz anatomy? Where do you find it? Describe its structure and importance.

    4. Write an account on Shibpur Botanical Garden and Royal Botanic Gardens, Kew (England).

  2. What is polyembryony? Describe the practical value of polyembryony. 60

  3. Answer the following questions

    1. What is palynology? Describe the applications of palynology.

    2. Describe the origin of wheat, maize and rice. 30 × 2 = 60

  4. Give salient features of flower of the following families. Give economic importance of three plants from each family 15 × 4 = 60

    1. Ranunculaceae

    2. Euphorbiaceae

    3. Dipterocarpaceae

    4. Orchidaceae



  1. Answer any three of the following. Each part should be answered in not more than 200 words. 20 × 3 = 60

    1. What is micro-propagation? List the various ways this technique can be used to practical advantage.

    2. What determines a sex-linked trait? Give two examples.

    3. Explain ‘test of significance’ and comment on its application in Botanical Research.

    4. Briefly review the methods adopted for determining distance between two genes on a chromosome.

  2. Describe the extra cellular matrix of a plant cell. What is the relationship of plasmodesmata to the extracellular matrix? 60

  3. How is recombinant DNA produced? What applications have been found for recombinant DNA? 60

  4. Distinguish between: 20 × 3 = 60

    1. Transcription and translation

    2. Spontaneous and induced mutations

    3. Binomial Distribution and Poisson Distribution.


  1. Answer any three of the following. Each part should be answered in not more than 200 words. 20 × 3 = 60

    1. What is oxidative phosphorylation? What is its significance?

    2. Define phototropism. What pigment (s) function as the photoreceptor for phototropism? Give evidence to support your conclusion.

    3. What are cytokinins? Give an account of roles they play n plant growth and development.

    4. What are biomes? Explain, will examples, how climate determines what biome occurs in a region.

  2. Review the Crassylacean acid metabolism (CAM). In what significant way does CAM differ from C4 metabolism? 60

  3. Describe how plants may be injured by water stress. In what way are freezing stress and salt stress similar to water stress?

  4. Give concise answers to the following: 20 × 3 = 60

    1. Explain why temperate forests and woodlands are less productive and diverse than tropical forests.

    2. How are endangered species listed in the Red Data Books?

    3. What is the function of leg hemoglobin in symbiotic nitrogen fixation?

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