IAS UPSC (CSE) Mains 2006: Botany

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Paper-I

Section A

  1. Answer any three of the following in not more than 200 words each: (20 × 3 = 60)
    1. What is bioremediation?
    2. Briefly discuss the phyletic position of photobionts.
    3. Highligh the uniqueness of the cell structure of Anthoceros.
    4. What is polarity and how does it affect differentiation?
  2. How do the following differ from each other: (20 × 3 = 60)
    1. Hybrid from Cybrid
    2. Cryptogams from Archegoniates
    3. Sporophyte from Gametophyte (in lower organisms)
  3. Describe the following: (20 × 3 = 60)
    1. Molecular basis of infection
    2. Practical application of ovule culture
    3. Microbes as indicators of pollution
  4. Draw neat and well-labelled diagrams to show: (20 × 3 = 60)
    1. Lytic cycle
    2. Diagnostic stages of any two powdery mildews
    3. L S sporocarp of Marsilea

Section B

  1. Answer any three of the following in not more than 200 words each: (20 × 3 = 60)
    1. What are the symptoms and causes of hay fever?
    2. Describe the morphological nature of commercial cotton, clove and saffron.
    3. Describe the phyletic position of Magnoliaceae.
    4. Citing suitable examples explain what is meant by ‘form genus’
  2. With the help of suitable diagrams explain: (30 × 2 = 60)
    1. Development of a bisporic embryo sac
    2. Vavilovian centres of origin of crop plants
  3. Discuss the following: (60)
    1. Alpha and Omega taxonomy
    2. Ethnobotany and its importance
    3. Nemec phenomenon
  4. Describe the following: (20 × 3 = 60)
    1. Distribution in India of the genus yielding “Taxol”
    2. Phenomenon of apomixis and its importance
    3. Commonalities and differences between Cyeadofilicales and Cyeads

Paper-II

Section A

  1. Write short notes on any three of the following in about 200 words each: (3 × 20 = 60)
    1. Structure of plasma membrane
    2. Polytene chromosomes
    3. DNA damage and repair
    4. Molecular markers in plant breeding
  2. Answer the following questions
    1. Explain linkage and crossing-over. Describe the methods of construction of gene maps (30) .
    2. What are mutations? Describe different types of mutations and add a note on chemical mutagens (30) .
  3. Explain the following with suitable examples:
    1. Techniques of breeding self-pollinated crops (20) .
    2. Protoplast culture and its importance (20) .
    3. Uses and applications of correlation and regression analysis in plant genetics (20) .
  4. Answer the following questions
    1. Explain the mechanism of DNA replication (20) .
    2. Discuss cytoplasmic inheritance: (20)
    3. Describe in brief the regulation of gene expression in eukaryotes (20) .

Section B

  1. Answer any three of the following. Each part should be answered in not more than 200 words: (20 × 3 = 60)
    1. Discuss the role of any three trace elements in plant nutrition. Give their deficiency symptoms.
    2. Explain the mechanisms of respiratory functions in plants.
    3. Discuss the strategies for conservation of endemic and endangered plants.
    4. Describe the causes and consequences of greenhouse effect
  2. Answer the following questions
    1. Describe the photosynthetic carbon assimilation in C3 and C4 plants (20) .
    2. Explain the factors that affect photosynthesis. Define photosynthetic efficiency of crops (20) .
  3. Answer the following questions
    1. Write an account of the physiological changes that occur during high temperature stress. How plants have adopted physiologically for tolerance of high temperature stress (30) ?
    2. Describe the effects of metal stress on plant growth and development (30) .
  4. Answer the following questions
    1. Define succession. Explain different stages of succession with illustrations (30) .
    2. Enumerate the structure and functions of an ecosystem (30) .