IAS UPSC (CSE) Mains 1987: Botany

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  1. Answer any three of the following. Answer to parts (b) (c), and (d) should not exceed 200 words each:

    1. Write the correct technical term for the following:

      1. The condition resulting from the action of a mechanism in plants that prevents selffertilization.

      2. The maturation of anthers and stigmas in a flower at different times.

      3. Condition in ferns in which the sporangium develops from the inner daughter cell produced by the periclinal division of a superficial cell produced by the periclinal division of a superficial cell in the lamina.

      4. A cycle of reproduction occurring in Fungi Imperfect that involves genetic recombination without meiosis of fusion of gametes.

      5. habit in algae characterized by the presence of an upright and a prostrate system of filaments.

    2. Explain the differences between the development of an ascus and that of a basidium.

    3. How does rust disease of wheat spread in India?

    4. Explain the more important structural features and properties of plant viruses.

  2. Answer the following questions

    1. Describe the fern-like characters of Cycas.

    2. Discuss the morphological nature of the ovuliferous scale in conifers.

  3. Answer the following questions

    1. Describe the salient structural features of Blue green algae. Write a note on their importance in agriculture.

    2. Write about the unique features of the sporophyte in Anthoceros, Briefly point out the evolutionary trends in the sporophyte in Bryophyte.

  4. Answer the following questions

    1. Describe the micro gametophyte development in Selaginella. Draw labelled diagrams.

    2. Discuss the morphological nature of sporocarp of Marsilea.

Section B

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

    1. Discuss the modern trends in taxonomy.

    2. Describe the events in the development of a fruit.

    3. Describe how secondary growth takes place in Dracaeana.

    4. Describe the mechanism of pollination in Salvia.

  2. Answer the following questions

    1. Discuss the classical concept of carpel. How is placention (axile and practical) explained on the basis of this concept?

    2. Describe the different types of nodal anatomy in angiosperms. Write a note on the evolutionary trends in nodal anatomy.

  3. Write the salient features of any four of the following:

    1. Peperomia type of exbryo-sac.

    2. Inflorescence of Euphorbiaceae.

    3. Androecium in the Asclepiadanceae.

    4. The primitive carpel

    5. Hypanthodium

  4. Answer the following questions

    1. Explain how clonal propagation can be done through tissue culture.

    2. What is the importance of isolation and culture of plant protoplasts? How are protoplasts isolated from leaves?

    3. Explain the phenomenon of Polarity giving examples.


Section A

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

    1. How does wobble hypothesis explain the functioning of highly degenerate genetic code?

    2. What is a nucleosome? Describe the structure and function of heterochromatin.

    3. Explain the functional integration of endoplasmic reticulum and Golgi apparatus as a part of endo-membrane system.

    4. Describe the structural and functional differentiation within fret and grana lamellae of chloroplast.

  2. Discuss the experimental evidence to prove that mutations in bacteria are random and spontaneous and not directed. What are the advantages of replica plate method?

  3. Discuss the salient features of Neo-Darwinian evolutionary hypotheses on origin of species.

  4. Answer any two of the following:

    1. Discuss the current concepts on the origin and autonomy of mitochondria.

    2. What is androgen sis? Discuss its significance in crop improvement.

    3. What is operon concept? How does it explain the induction and repression of enzyme biosynthesis?

Section B

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

    1. Explain carrier hypothesis for ion uptake.

    2. What are the causes for SO2 pollution in air? Describe its effect on plants.

    3. Discuss the functions of URBISCO under different levels of CO2 and O2.

    4. Critically assess the potential use of Azolla-Anabaena azollae system for replacing commercial nitrogenous fertilizer in rice cultivation.

  2. What are the roles of light and temperature in germination of seeds? Give a critical account of the hormonal regulation of seed germination.

  3. Answer the following questions

    1. It is reported that a leguminous plant Cassia sericea is being used as a biological agent in eliminate parthenium hysterophorus, an ubiquitious and pernicious weed. What is this phenomenon known as? Discuss the various ecophysiological processes that are possibly involved in this method of control.

    2. Explain the cyanide-insensitive pathway or alternate oxidize pathway. Under what conditions does it operate?

  4. Answer the following questions

    1. Describe the characteristics of a tropical rain forest as a climax community. Explain how its stability is achieved.

    2. What is ‘shifting’ or ‘podu’ cultivation? What are its ill-effects? How far can social forestry solve this problem?

    3. Describe the uses and the morphological nature of the plant parts yielding economic products in the following:

      1. Shorea robusta

      2. Glycine max

      3. Trachyspermum amml

      4. Psoralea corylifolia

    4. List three major plant products exported from our country. Write their botanical names and the States in which they are cultivated.

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