Plant Growth Hormones Questions and Answers Objective Type

1. After unidirectional light is received, auxin moves to the shady side of a stem and then e stem towards the light. Which step in this sequence represents transduction
(A) Curving of stem towards light
(B) Sensitivity of a receptor to light
(C) Auxin movement towards the shady side
(D) All of the above are correct

2. Phytochrome ?
(A) Is a plant pigment
(B) Is present as Pfr during the day
(C) Activates regulatory proteins
(D) All of the above are correct

3. Which of the following is correct statement ?
(A) Only stems show positive gravitropism
(B) Only roots show positive gravitropism
(C) Both stems and roots show positive gravitropism
(D) Both stems and roots show negative gravitropism

4, Ethylene is employed for ?
(A) Ripening of fruit
(B) Stimulation of cell division
(C) Increasing light
(D) All of the above

5. Growth hormone obtained from a fungus is-
(A) Auxin
(B) Gibberellin
(C) Cytokinin
(D) Phytokinin

6. Abscisic acid (ABA), which is generally called a stress hormone, also-
(A) Stimulates cell division.
(B) Accelerates fruit ripening
(C) Helps in stomatal development
(D) Aids in fruit development

7. Apical dominance is due to
(A) Absence of auxin and gibberellin in apical bud
(B) High concentration of gibberellin in apical bud
(C) High concentration of auxin in terminal bud.
(D) High concentration of auxin in lateral bud

8. Gibberellin promotes
(A) Leaf fall
(B) Root elongation
(C) Seed germination
(D) Seed dormancy

9. Indole acetic acid (IAA) precursor is
(A) Leucine
(B) Tyrosine
(C) Phenylalanine
(D) Tryptophan

10. In higher plants, cell enlargement is due to hormone ?
(A) Florigen
(B) Auxin
(C) Gibberellin
(D) Cytokinin