IAS UPSC (CSE) Mains 1986: Botany

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Section A

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

    1. Write the correct technical term for the following

      1. Developmental pattern by which the outer most layers of xylem differentiate before any others.

      2. Process of sexual reproduction in which a large nonmotile egg is fertilized by a smaller male gamete.

      3. Hairlike structure common in lower organisms used for absorption and anchorage.

      4. Accessory fruit developed from a floral receptacle rather than from an ovary.

      5. A kind of inflorescence in which flowers are located sessile on an elongated axis.

    2. What is syngamy? Does it occur in bacteria? Explain.

    3. Compare and contrast the life cycles of Saprolegnia and Vaucheria.

    4. Present the differences that distinguish liverworts, bornworts and mosses. What are the common characteristics shored by all of them?

  2. Answer the following questions

    1. Do you consider that heterospory in pteridophytes has led to seed habit? Explain.

    2. Would you designate the life cycle of Pinus as haplontic, diplonaplontic or diplomatic? Explain suitably.

  3. Answer the following questions

    1. What is the unique feature of Ginkgo with respect to its evolutionary history?

    2. Differentiate between carposporophyte and tetrasporophyte. What is the ploidy of each?

    3. Why are yeasts included in Ascomycota? Explain with reasons.

  4. Answer the following questions

    1. Outline the nature of vascular system in Equisetum and ferns. Which is more advanced? Why?

    2. Why are slime molds sometimes classified as animals? Explain how they are plant-like and give the characteristics of the different classes of slime molds.

Section B

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

    1. What is quiescent centre? Briefly explain the nature of apical ineristems.

    2. Summaries the development of different types of embryo sacs in angiosperms.

    3. Discuss the role of biosystematics in the under-standing of the taxonomy of angiosperms.

    4. Explain the role of symmetry and polarity in plant morphogenesis.

  2. Discuss any two of the following:

    1. Distinctive anatomy of the monocotyledonous stem with suitable diagrams.

    2. The role of light in morphogenesis.

    3. The most important applications of tissue culture method in agriculture.

  3. Describe the uniqueness of the following:

    1. Androecium in Asclepiadaceae.

    2. Corolla in Scrophulariaceae.

    3. Pollination in Labiatate.

    4. Gynoecium in Cyperaceae.

    5. Fruite and seed in Umbelliferae.

  4. Answer any three using not more than 200 words for each part:

    1. Discuss the merits and demerits of the system of classification proposed by Hatchinson.

    2. Give the most important features of the family palmae and discuss its phylogenetic relationships.

    3. Bring out the importance of palynology in the phylogenetic systems of classification.

    4. Present a critical account of the development of microsporangium in angiosperms.


Section A

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

    1. Distinguish between lysosome and peroxisome.

    2. How are adjacent cells in higher plants held together? Describe the functions of plasmodesmatta.

    3. Mitochondria is a cell within a cell. Discuss.

    4. The use of Schiff's aldehyde reaction.

  2. Explain the fluid-mosaic model of biomembrane.

  3. Describe the experiments that led to the formulation of Operon theory

  4. Answer any three of the following:

    1. Explain the coacervate hyyothesis.

    2. Enumerate genetic evidences for evolution.

    3. How have isolation mechanisms influcnced evolution?

    4. Differentiate between plasmid and cosmid.

Section B

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

    1. List the major chemical group found in

      1. cell wall

      2. chromosome

      3. ribosome

      4. oil droplet

      5. uncleosome.

    2. When a potato tuber is cut, it turns brown, Explain.

    3. ‘Mangroves protect the coastal soil from erosion.’ Justify the claim.

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

  2. Why is Hatch-Slack pathway of photosynthesis considered efficient? Describe the pathway.

  3. Answer the following questions

    1. Describe energy flow in an ecosystem.

    2. An environmental scientist was ship-wrecked and found himself in a barren-rock island with very little vegetation. Fortunately, a large box containing corn flakes and a box containing a dozen hens were also found in the island by the scientist. The scientist wants to live while awaiting rescue. When he should do in order to service as long as possible? Will he

      1. eat the corn flakes first

      2. eat the hen first

      3. feed the hens

      4. maintain hens for egg production?

  4. Answer the following questions

    1. What is ethno botany? Are economic botany and ethonobotany interrelated? Describe.

    2. Outline the important bioassays used to detect auxin and abscises acid.

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