IAS Mains Botany Papers 1991

IAS Mains Botany 1991


Section A

  1. Answer any three of the following parts. Answer should not exceed 200 words for each:

    1. List the structural characteristics of the cyan bacteria. What are they included under the kingdom Monera and not in the kingdom Plantae?

    2. Outline a method by which water pollution can be controlled by bacteria.

    3. discuss the difference between a lysogenic and lytic pathway of multiplication of bacteriophages inside the host cell.

    4. Explain the difference between active and passive immunity.

  2. Answer the following questions

    1. Name the causal agent, two characteristic symptom expression of the following plant disease:

      1. Bunchy top of banana (Musa sp.)

      2. White rust of mustard (Brassica campestris L.)

      3. Citrus canker (Citrus aurantifolia Swingle) also (C. Sinensis (L.) Osbeck)

      4. Yellow rust of wheat (Triticum vulgare Host)

      5. root-knot of potato (Solanum tuberosum L.)

    2. Explain the concept of physiology of parasitism by suitable examples.

  3. Answer the following questions

    1. Discuss the adaptations for land life evident in the bryophytes.

    2. Give a schematic representation of the life cycle of moss (no details are necessary) ad explain the existence of alternation of generations. How have experimental studies modified our understanding of the alternation of generations?

    3. Draw the structure of a vegetative cell of yeast (Scharomyces cervisiae). Explain the economic importance of yeast.

    4. In what ways in chara unique among the algae?

  4. Discuss the resemblances and differences in the structure of Selaginella and Lycopodium.

Section B

  1. Answer any three of the following parts. Answer should not exceed 200 words for each:

    1. Explain methods of proving that a plant is an apomict and capable of inducing parthenocarpy.

    2. Which characteristics of fowers are considered to be evolutionarily advanced and which are considered to be primitive?

    3. Write briefly about the following:

      1. Casparian band

      2. Explain the differences in the functional leaf anatomy of C3 and C4 plants

      3. Pollen as allergens

      4. Fusifrom initials and ray initials

    4. Explainvery briefly the economic importance of

      1. Euphorbiaceae

      2. Compositae

      3. Gnetales

      4. Coconut palm

  2. Answer the following questions

    1. What is tot potency? Discuss the significance of regenerating plants from single cells or protoplasts under aseptic conditions.

    2. Explain the advantages of micropropagation using the plant tissue culture methodology.

  3. Selecting suitable examples form gymnosperms, explain the following conditions and their significance.

    1. Dioecism

    2. Flagellated sperm

    3. Pollination droplet

    4. Cleavage polymbryony

    5. Evegreen foliage

  4. Write short notes on the following terms, citing the genus and the family (angiosperm) in which these are found:

    1. Pollinium

    2. Capitulum

    3. Cyathium

    4. Bicollateral vascular bundles

    5. Pome


Section A

  1. Answer any three of the following in not more than 200 words for each part:

    1. Gives evidence for the correlation of cytological crossing over genetic recombination.

    2. How do you distinguish between DNA polymerase, RNA polymerase and reverse transcriptase? What are their products?

    3. Describe the ultra structure and function of endoplasmic reticulum.

    4. What are aneuploids? How do they originate? Give suitable examples and explain their significance.

  2. Answer the following questions

    1. What is meant by gene amplification? Discuss giving examples.

    2. Highlight the most important principles employed in plant breeding.

  3. Write a critical essay on the principal modes of gene transfer in bacteria.

  4. Answer any two of the following:

    1. What are polar mutations? Discuss their role and significance.

    2. Examine the concept of gene pool in relation to evolution in natural populations.

    3. Discuss the principal theories regarding organic evolution.

Section B

  1. Answer any three of the following in not more than 200 words for each part:

    1. What is light harvesting Complex? Explain its role in relation to the function of Reaction Centre.

    2. Define senescence. Discuss the various types of senescence and their role in plant development.

    3. Explain the physiology and biochemistry of guard cell function.

    4. How are fats converted ton carbohydrates in plants? Explain the uniqueness of the pathway.

  2. Present a brief essay on the diversity in photosynthetic carbon reduction and the role of different modes in adaptation to environment.

  3. Answer any two of the following:

    1. What is social forestry? Explain its principles and practice.

    2. Briefly describe the concept of community in relation to its dynamics.

    3. Discuss the mechanism of transport of organic solutes in phloem.

  4. Answer the following questions

    1. What is Biosphere? What is its main subdivision? Explain the concepts of matter and energy in the functioning of the biosphere.

    2. Give complete botanical names of the following plants their products, their families, the morphological natures of the part and the uses in each case

      1. Safflower

      2. Citronella

      3. Cloves

      4. Tea

    3. What are plant indicators? Give a brief account of their usefulness with specific examples.