Competitive Exams: Botany MCQs (Practice-Test 24 of 104)

    • Assertion (A): In plants, site of action of ethylene is close to its site of synthesis.
    • Reason (R): Ethylene is insufficiently soluble in water to be transported in the form of aqueous solution.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): Plants grow quicker during day than during night.
    • Reason (R): The food which is essential for growth is synthesized by the green plants only in the presence of sunlight.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): C14 isotope is more widely used in biochemical studies than C11 isotope.
    • Reason (R): C14 isotope is radioactive and found in nature.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 Zn deficient plants, resupply of Zn increases auxin content.
    • Reason (R): Zn is essential for the synthesis of auxin.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 summer months, most of the plants show mid day closure of stomata.
    • Reason (R): The rate of absorption of water increases with the increase in temperature.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 thylakoids isolated from chloroplasts are exposed to light in the presence of CO2 and H2O, hexose's are not formed.
    • Reason (R): Carbon assimilation is a dark reaction and does not take place in light.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 woody plants growing in temperate regions, the resumption of cambial activity in the spring is related to the new growth from buds.
    • Reason (R): The initial stimulation of cambial activity is related to the formation and distribution of growth hormones in the spring.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): Dormancy of seed is an epigenetic trait.
    • Reason (R): Dormant seeds can be induced to germinate by manipulating the environmental conditions around the seed.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): Alloploidy has led to the evolution of many crop plants.
    • Reason (R): Alloploidy leads to the pairing of homologous chromosomes resulting in fertile hybrids.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 the study of DNA analysis for biosystematics applications, the chromatin values are estimated.
    • Reason (R): Morphologically similar organisms appear to have similar amounts of DNA in their genome.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 pollen wall proteins are contributed by the two generations in the life cycle of a flowering plant.
    • Reason (R): The exine proteins are of saprophytic origin and the in tine proteins are of gametophyte origin.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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 stiffness and rigidity of wood is due to the presence of cellulose, hemicelluloses and lignin.
    • Reason (R): The degree of stiffness depends upon the amount of cellulose in the cell wall.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): RuBP carboxyl's is the most abundant protein on earth.
    • Reason (R): RuBP carboxyl's can constitute up to 30 percent of the protein in a leaf.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): Triple dwarf mexican wheat cultivar ‘Sonoar 64’ was introduced in India from outside:
    • Reason (R): Dwarfness increases the productivity.
    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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): Male trees of Ginkgo biloba are not preferred in gardens.
    • Reason (R): Their seeds contain Butyric

    Acid, which upon decomposition emits foul smell like rancid butter.

    1. Both A and R are true & R is the correct explanation of A

    2. Both A and R are 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