Competitive Exams: Botany MCQs (Practice-Test 100 of 104)

  1. Senescence of detached leaves can be delayed by the use of

    1. Auxin

    2. Gibberellins

    3. Cytokines

    4. Ethylene

  2. Match List I (phenomena) with List II (growth regulators) and select the correct answer

    List-I List-II
    1. Root differentiation

    2. Vegetative bud differentiation

    3. Flower bud differentiation

    4. Fruit development

    1. Kinins followed by auxins

    2. Auxins followed by kinins

    3. Auxins plus gibberellins

    4. Auxins plus carbohydrates

    • A
    • B
    • C
    • D
      • 4
      • 3
      • 1
      • 2
      • 4
      • 1
      • 2
      • 3
      • 3
      • 2
      • 1
      • 4
      • 1
      • 4
      • 3
      • 2
  3. Which of the following pairs are correctly matched?

      • Angular leaf-spot:
      • Xanthomonas of cotton malvacearum
      • Wilt of cotton
      • . Fusarium oxysporum
      • Leaf spot of cotton:
      • Alter aria lini
      • Red rot of sugar-cane:

    Colletcrichum falcatum

    Select the correct answer

    1. 1, 2 and 3

    2. 1, 3 and 4

    3. 1, 2 and 4

    4. 2, 3 and 4

  4. In which one of the following pathogens do the cells of promycelium after the germination of teleutospore produce infection hyphae instead of basidiospores?

    1. Ustilago scitaminae

    2. Tilletia foetida

    3. Tilletia tritici

    4. Ustilago tritici

  5. Which one of the following substances plays an important role in biochemical defense of host plants?

    1. Mycotoxin

    2. Phytoalexin

    3. Pathotoxin

    4. Vivotoxin

  6. Match List I (enzymes of pathogens) with List II (host substrates) and select the correct answer

    List-I List-II
    1. Pectin methyl esterase

    2. Cx enzyme

    3. Polygalacturonase

    4. C1 enzyme

    1. Linear anhydroglucose chain

    2. Pectic acid

    3. Native cellulose

    4. Pectin

    • A
    • B
    • C
    • D
      • 4
      • 3
      • 2
      • 1
      • 4
      • 1
      • 2
      • 3
      • 2
      • 3
      • 4
      • 1
      • 2
      • 1
      • 4
      • 3
  7. The following diagrams (leveled 1, 2, 3, 4) are reproductive bodies of pathogenic fungi: Among these, those representing the products of sexual reproduction would include

    1. 2 and 4

    2. 1 and 3

    3. 3 and 4

    4. 1, 3 and 4

  8. Which one of the following microorganisms is widely used for the biological control of plant diseases?

    1. Trichoderma viride

    2. Fusarium cubense

    3. Streptomyces scabies

    4. Bacillus subtilis

  9. Which one of the following is the basis of biological control of crown gall?

    1. Agro bacterium radiocasted strains contain a plasmid which directs the synthesis of bactenocin

    2. The Ti (tumour inducing) plasmid in Agro bacterium tumefactions is integrated with host plant DNA and is transcribed into mRNA

    3. The cloning strategy leading to a composite (chimeric) plasmid harboring two or more genes that code for distinct bacteriocins against phytopathogenic bacteria

    4. Agobbacterium radiobacter plasmid interferes with the production of auxin by a tumefaction

  10. Which of the following pairs are correctly matched?

      • Datura stramonium
      • Solanine
      • Papaver somniforum
      • Narceine
      • Cannabis sativa
      • Cocaine

    Select the correct answer

    1. 1, 2 and 3

    2. 1 and 2

    3. 1 and 3

    4. 2 and 3

  11. Which of the owing statements regarding the maintenance of carbon cycle in the biosphere are correct?

    1. Plant utilize solar energy to convert CO2 and water into cellular materials and produce oxygen that animals consume.

    2. Oxygen produced by the plants during carbon assimilation is not a byproduct.

    3. Energy used by an animal comes form the oxidation of plant material releasing CO2 that escapes into the atmosphere.

    4. All decaying organic matter on the earth is ultimately degraded by molds and bacteria to yield CO2 that escapes into the atmosphere

    Select the correct answer.

    1. 2, 3 and 4

    2. 1, 3 and 4

    3. 1 and 2

    4. 1, 2, 3 and 4

  12. Which one of the following plants is the source of gum-Arabic

    1. Coffea arabica

    2. Prospis spiciagera

    3. Albizzia lebbek

    4. Acacia sengal

  13. Match List I (bioinsecticidal compounds) with List II (plant species) and select the correct answer

    List-I List-II
    1. Rotenone

    2. Nimbidin

    3. Dernissine

    4. Pyrethnim

    1. Derris elliptical

    2. Azadirachta indicia

    3. Solanum khasianum

    4. Chrysanthemum cineraria folium

    • A
    • B
    • C
    • D
      • 1
      • 2
      • 3
      • 4
      • 1
      • 2
      • 4
      • 3
      • 2
      • 1
      • 3
      • 4
      • 2
      • 1
      • 4
      • 3
  14. Which one of the following groups of characteristics is applicable to the timber obtained from Sal (Shorea)?

    1. Strong, durable, moderately heavy, takes good polish.

    2. Strong, durable, heavy, does not take good polish

    3. Strong, durable, heavy, takes good polish

    4. Not strong, durable if not exposed, light, does not take good polish

  15. The following plants contain caffeine:

    1. Coffee

    2. Yucca

    3. Cola

    4. Tea

    5. Cocoa

    The correct sequence of the ascending order (lowest first, highest last) of the caffeine content of these plants is

    1. 5, 1, 4, 3, 2

    2. 1, 5, 3, 4, 2

    3. 1, 5, 4, 2, 3

    4. 5, 1, 3, 4, 2