IAS Mains Botany Papers 1990

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IAS Mains Botany 1990


Section A

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

    1. Write briefly about the following:

      1. A vascular land plant more primitive than rhynia

      2. A plant disease beneficial to man

      3. An edible alga grown commercially by sea-farming

      4. A bacterium commercially exploited for antibacterial drug production.

      5. A carnivores fungus.

    2. Distinguish between ‘virus’ and ‘viroids’ with suitable examples.

    3. What are monoclonal antibodies? How are they produced? Mention their importance.

    4. What are Target-specific fungicides? Name three such fungicides and mention their modes of action.

  2. Answer the following questions

    1. Comment on any two of the following:

      1. Generalized and specific transduction

      2. Evidene of role of pectin hydrolase's and transeliminases in plant disease development

      3. Post-infectional biochemical defence mechanism in plants.

    2. Name the causal agent, primary inoculum and its source, two characteristic symptom expressions, secondary inoculum and specific control measures used by the farmers for the following plant diseases:

      1. Downy mildew of Bajra

      2. Rust of Coffee

      3. Bacterial wiet of Potato

      4. Sandal spike

      5. Ear-cockle of Wheat.

  3. Answer the following questions

    1. Describe the morphology and anatomy of the corn of Isoetes. Trace the origin of the taxon from arborescent lycopods.

    2. Describe the sporophyte morphology of Azolla with special reference to its argonomic use as a bio-fertilizer.

  4. Answer the following questions

    1. Comment on any Three of the following:

      1. Triphasic life-cycle in algae

      2. Ballistospores and mechanism of their discharge

      3. Differences between sexual and parasexual recombination

      4. Similarities and dissimilarities between photo-synthetic systems of blue-green and green algae

    2. Attempt any two to the following:

      1. State the distinguishing features of saprophytes of Sphagnidae, Andreacidae, and Bryidae with sketches and examples

      2. Control of oil pollution of sea-water by microbes

      3. Economic, medicinal and ecological importance's of bryophytes of man.

Section B

  1. Answer any three of the following questions:

    1. Write briefly about the following:

      1. An angiosperm with open carpel

      2. A herbaceous gymnosperm

      3. A saprophytic angiosperm

      4. A dicotyledonous with C4 pathway

      5. A monocot with secondary growth

    2. Comment on the floral structure, relationships, and economic importance of Ephedra.

    3. Distinguish between the cellular and helobial endosperm development with sketches and examples.

    4. What are somatic hybrids? How are they produced? Mention their importance to manking with suitable examples.

  2. Answer the following questions

    1. Enumerate the families of Conferrals giving characteristic features, distribution and an Indian examples of each of them.

    2. What is numerical taxonomy? Briefly state the methods employed in and importance of this taxonomy.

  3. Answer the following questions

    1. Answer any two of the following:

      1. Outline the salient features of the classification by Bentham and Hooker. What are the merits and demerits of this system?

      2. Briefly comment on the origin of angiosperms.

      3. Importance of the study of photochemistry in taxonomy.

    2. Answer the below questions

      1. State the distinguishing characters of Rosaceous and the affinities of the taxon with Rannunculaceae and Leguminous. Mention five India fruit plants of the family.

      2. Describe the shoot apex organization of angiosperms in the light of recent researches.

  4. Answer the following questions

    1. Place the following genera to their respective families and indicate their economic importance:

      1. Elaeis

      2. Manihot

      3. Arachis

      4. Cephaelis

      5. Nigella

    2. Distinguish between:

      1. Cereals and millets

      2. Omithophily and chiropteriphily

      3. utricularia and Aldrovanda

      4. Plasmodesmata and Ectodesnata

      5. Sorosis and Syconus.


Section A

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

    1. What are peroxisomes and glyoxysomes? Present brief account of their functions in the light of modern work.

    2. Define epitasis. Explain the Patten of interactions involved with a suitable example.

    3. Briefly describe the cloning of eukaryotic genes in E. Coil.

    4. Discuss the structure and importance of polygene chromosome in the study of gene regulation.

  2. Answer the following questions

    1. Write a short account on male sterility and its significance in plant breeding.

    2. Mention the condition required to maintain the hardy-Weinberg equilibrium over several generations. How does the equilibrium get altered by a charge in these conditions?

  3. Give the characteristics that a substance must possess to be a hereditary carrier. Discuss the role of genetic code in eukaryotic protein synthesis.

  4. Answer any two of the following:

    1. Explain gene evolution by mutation through duplication.

    2. Discuss the significance of cytoplasm inheritance and its importance in hybridization.

    3. Present critical evidences for the concept of organic evolution.

Section B

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

    1. What is photo system II? Discuss the structure and function.

    2. Describe mitochondrial electron transport chain and its relation of oxidative phosphorylation.

    3. Give the modern concept of the mechanism of stomata opening and closure.

    4. Discuss the hormonal control of seed dormancy and germination.

  2. What is C4 photosynthesis? In what groups of plants does this occur? Explain its high efficiency with special reference to productivity.

  3. Answer any two of the following:

    1. Forest types of India

    2. The role of micronutrient elements in plant nutrition with particular reference to zinc and manganese.

    3. Action of phytahrome in the physiology of flowering.

  4. Answer the following questions

    1. Write briefly about the conservation of ecosystems.

    2. Give complete botanical names of the following plants, the family to which they belong, the morphological nature of the parts yielding the economic products and their uses:

      1. Jute

      2. Saffron

      3. Teak

      4. Rubber

    3. discuss in brief the major centers of origin of cultivated plants in the world with particular references to origing of wheat.

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