Auxin MCQ Questions and Answers: 

1. Which of the following are transport modes of auxin in plants?

A. Endocytosis and efflux

B. free diffusion

C. Aid in diffusion

D. active transport

Answer: D

2. The physiological function of growth hormone does not include______

A. Promote fruit ripening

B. Promotes longitudinal elongation of cells

C. Promote rooting of cuttings

D. Prevent flower drop

Answer: A

3. Which one of these is commonly used synthetic auxin?

A. NAA

B. IAA

C. IBA

D. GA

Answer: A

4. Which of the following is not a natural auxin?

A. Indole acetic acid

B. Naphthalene acetic acid

C. Indole acetaldehyde

D. Indole ethanol

Answer: B

5. The hormones associated with plant phototropism are mainly________

A. growth hormone

B. Cytokinin

C. Ethylene

D. Abscisic acid

Answer: A

6. The hard way to treat plants with auxin in horticulture is________

A. Obtain seedless fruit

B. Promote fruit ripening

C. Promote the rooting of cuttings

D. use as herbicide

Answer: B

7. Which of the following is a natural auxin?

A. Indole acetic acid

C. Indole acetaldehyde

D. Indole ethanol

D. All of these 

Answer: D

8. Which of the following combination of hormones will promote differentiation of shoot as well as root in tissue culture?

A. Gibberellin and abscisic acid

B. Auxin and abscisic acid

C. IAA and gibberellin

D. Auxin and cytokinin

Answer: D

9. This bioassay is used to detect the presence of auxin_______

A. Only tobacco pith culture

B. Tobacco pith culture and Avena curvature test

C. Tobacco pith culture and Split pea stem curvature test

D. Split pea stem curvaturetest and Avena curvature test

Answer: D

10. Which of the following statements about the physiological role of auxin is correct?

A. Lateral bud auxin synthesis is inhibited when terminal bud growth is dominant

B. Polar transport of auxin in oat coleoptiles is independent of light direction

C. The natural growth process of strawberry fruit is not related to auxin but to ethylene

D. Active transport of auxin from the base of the coleoptile tip into the agar block in Winter’s experiment

Answer: B

11. Which of these is not a function of auxin?

A. inducing callus formation

B. inducing dormancy

C. enhancing cell division

D. maintaining apical dominance

Answer: B

12. In plant cells, indoleacetic acid is mainly produced from tryptophan by a series of enzymes. Which of the following statements is correct______

A. Indoleacetic acid can be synthesized in large quantities in the coleoptile

B. Tryptophan contains at least one amino group and one carboxyl group

C. Indoleacetic acid is a regulatory protein

D. Excess tryptophan inhibits the synthesis of indoleacetic acid

Answer: B