Competitive Exams: Botany MCQs (Practice-Test 39 of 104)

  1. As per the international society of social science, what is the size of the particles of fine sand in the soil?

    1. 0.001 mm to 0.002 mm

    2. 0.002 mm to 0.02 mm

    3. 0.02 mm to 0.20 mm

    4. 0.20 mm to 2.00 mm

  2. With which of the following is the name of Louis Pasteur associated?

    1. Explanation of the formation of simple organic molecules in the early atmosphere of earth.

    2. The proposition of the composition of gases in the early atmosphere of earth.

    3. Disproving the theory of spontaneous generation of organisms.

    4. Proposition that the first photosyrhetic organisms were cyanobacteria.

    • Assertion (A): Ferreoxin carries two electrons at a time.
    • Reason (R): The active site of ferredoxin consists of two iron atoms bound to two sulfur atoms.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Rice seeds germinate and begin to grow under flooded conditions.
    • Reason (R): Embryos of rice seeds carry out facultative anaerobic respiration.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Citric acid has lesser Respiratory Quotient in comparison to lipids.
    • Reason (R): Citric acid has relatively more oxygen in comparison to lipids.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): If the oat seedlings are exposed to unilateral illumination, the stem bends towards the light.
    • Reason (R): An auxin gradient is established in the coleoptile by the destruction of auxin in the lighted side and extra synthesis of auxin in the darker side.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): In pear fruit, the inner tissue is the true fruit and the outer tissue is the accessory fruit.
    • Reason (R): In pear, the fruit develops from inferior Ovary.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The rate of DNA replication is much faster in E coil than in eukaryotes.
    • Reason (R): The length of Okazaki fragments that result from DNA Polymer I activity are much shorter in prokaryotes than in eukaryotes
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Orchid seeds lack endosperm in flowering plants.
    • Reason (R): Double fertilization is absent in orchids.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Segemental allopolyploids where all the chromosomes are homologous.
    • Reason (R): Segmental allopolyploids can be identified by their meiotic behavior.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The expression of each gene is independent of the other genes.
    • Reason (R): Genes follow the law of independent assortment as per Mendel's studies.
    1. Both A and R are individually true and R is the correct explanation of A.

    2. Both A and R are individually true but R is not the correct explanation of A.

    3. A is true but R is false

    4. A is false but R is true

  3. Consider the following statements: In vitro micro propagation has the advantages of:

    1. Range of variability

    2. Year round availability

    3. Small size of explants

    4. Production of disease free prop gules.

    Which of the statements given above are correct?

    1. 1, 2 and 4 only

    2. 2, 3 and 4 only

    3. 1 and 3 only

    4. 1, 2, 3 and 4

  4. Who of the following is associated with the discovery of ‘Restriction endow-nuclease’

    1. Hamilton Smith

    2. H. G. Khorana

    3. Marshall Nirenberg

    4. S. B. Weiss

  5. Consider the following diseases of plants:

    1. Root knot of sugar-cane.

    2. Root rot of wheat.

    3. Wilt of cotton.

    4. Angular leaf spot of cotton.

    Which of these diseases is/are caused by fungi?

    1. 1 and 4 only

    2. 2 only

    3. 2 and 3

    4. 1, 3 and 4

  6. Which one of the following is a disease caused by zinc deficiency?

    1. Die back of rice

    2. Khaira disease of rice

    3. Black heart of potato

    4. Brown spot of rice