IAS Mains Botany Papers 1988

IAS Mains Botany 1988

Paper-I

Section A

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

    1. Give a precise definition of the following:

      1. Plasmid

      2. Cybrid

      3. Biocide

      4. Antithetic Theory

      5. Stele.

    2. Describe the different ways in which genetic variation is brought about in bacteria.

    3. How would you differentiate between a leafy liverwort and a moss?

    4. Compare the structure of female gametophyte in Cycas, Pinus, Ephedra and Gnetum. What conclusions do you draw from such a study?

  2. Answer the following questions

    1. Give an account of the importance of microbes in agriculture.

    2. What is the ecological significance of bryophytes?

  3. Answer the following questions

    1. Briefly describe the structure and life history of Fucus.

    2. Give an illustrated account of the structure, life history and economic importance of

    Claviceps.

  4. Answer the following questions

    1. Write about Sphagnum under the following headings:

      1. morphology

      2. Ecology

      3. Economic Importance

      4. Relationships.

    2. Describe the structure of Rhynia and discuss its evolutionary significance.

Section B

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

    1. Discuss the theories which explain the phenomenon of apical dominance.

    2. What does the term morphogenesis men's? Write briefly on the chemical factors controlling morphogenesis.

    3. Distinguish between the two major categories of self-incompatibility. Describe the different methods employed to overcome incompatibility.

    4. Write suitable illustrations, explain the differences between the anatomy of C3 and C4 plants.

  2. Answer the following questions

    1. Describe the three major modes of endosperm development.

    2. What is the difference between true polyembryony and false polyembryony? Give an illustrated account of adventives embryony.

  3. Answer the following questions

    1. What are the main features of the system of classification proposed by Bentham and Hooker? Discuss its merits and demerits.

    2. With suitable examples, explain the chief ways in which abnormal secondary growth occurs in the stems of dicotyledonous plants.

  4. Describe the characteristics of the following:

    1. Flower of Megnoliaceae

    2. Gynoecium of Cruciferae

    3. Androecium of Cucurbitaceae

    4. Fruit of Umbelliferae

    5. Inflorescence of Grandniece.

Paper-II

Section A

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

    1. Write brief notes on the functional interference of nucleus, cytoplasmic ribosome's and chloroplast in the synthesis of photosynthetic enzymes, and ribosomal and membrane proteins.

    2. Describe briefly gene amplification and discuss the possible role of genetic redundancy.

    3. Explain the structure and function of microtubles.

    4. Explain the methodology and use of differential and sucrose density gradient centrifugation.

  2. Answer the following questions

    1. Discuss the role of transposons in gene transfer.

    2. Unrelated phenotypic expressions in different parts of the organism are controlled, in certain cases, by a single gene and it is called pleiotropy, But, the general concept is that one cistron produces one polypeptide. Give at least two different explanations to reconcile this discrepancy.

  3. Explain the differences between Prokaryotic and Eukaryotic protein synthesis.

  4. Answer any two of the following:

    1. Explain a polar mutation, Under what conditions a nonsense mutation will not act as a polar mutation?

    2. Explain critically the role of genetic drift in evolution.

    3. What are the causes for male sterility? Briefly discuss the importance of male sterility in the improvement of crop plants.

Section B

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

    1. Explain the mechanism of facilitated diffusion. How does it differ from active transport?

    2. Discuss the ole of abscissas acid in stom a tal role in plants under salt stress.

    3. Describe nontoxic organic osmotic a and their role is plants under salt stress.

    4. Explain the experimental evidences for the functioning of photo systems I and II.

  2. Explain the causes for the apparent lack of Photo-respiration in C4 plants. Critically evaluate the various attempts to regulate photorespiration in C3 plants.

  3. Answer any two of the following:

    1. In the recent years, there is a dramatic change from the view of Ca2 + as a mineral nutrient to its present status as a key regulator of cellular activities and development. Discuss.

    2. Explain the causes for climacteric during the ripening of a fruit. Is climacteric in fruits qualitative or quantitative?

  4. Answer the following questions

    1. Explain the importance for recognition and study of biosphere reserves. Identify Indian biosphere reserves and their location and describe their distinctive ecological features.

    2. Describe the origin of rice.

    3. Describe the economic products obtained, their uses and the morphological nature of the parts yielding them, in the following:

      1. Cannabis Sativa

      2. Elcais Guinensis

      3. Leuaaena Leucocephala

      4. Dioscorea deltoidea.