Plant Growth and Development
Multiple Choice Question and Answers
1. The growth involves
(a) cell division
(b) cell elongation
(c) cell maturation
(d) all of the above
Answer: (d) all of the above
2. The substances which originates at the tip of stem and control the growth elsewhere are
(a) vitamins
(b) auxins
(c) enzymes
(d) florigen
Answer: (b) auxins
3. Who demonstrated that cut tip of canary grass seedling resumes phototropic sensitiveness when pasted back in its position?
(a) Darwin
(b) Palpitations
(c) Boysen-Jensen
(d) Went
Answer: (a) Darwin
4. Auxanometer is used for the measurement of
(a) auxins
(b) growth
(c) movement
(d) respiration
Answer: (b) growth
5. Gibberellins were first discovered from
(a) algae
(b) fungi
(c) angiosperms
(d) bacteria
Answer: (b) fungi
6. Dwarf plants can be made taller by
(a) gibberellins
(b) auxin
(c) cytokinin
(d) vernalin
Answer: (a) gibberellins
7. High concentration of synthetic auxins would
(a) kill the plants
(b) prevent lateral buds from growing
(c) control cell division
(d) cause phototropism
Answer: (a) kill the plants
8. Which one of the following is known to induce flowering in pineapple?
(a) Ethylene
(b) ABA
(c) Gibberellins
(d) Cytokinins
Answer: (a) Ethylene
9. Which of the following is not a naturally occurring hormone?
(a) 2 4-D
(b) GA3
(c) Zeatin
(d) IAA
Answer: (a) 2 4-D
10. The following is a growth inhibitor
(a) IAA
(b) ABA
(c) NAA
(d) GA3
Answer: (b) ABA
11. The auxins are abundantly produced in
(a) shoot
(b) root
(c) meristematic region of the shoot
(d) meristematic region of the root
Answer: (c) meristematic region of the shoot
12. Which of the following plant hormone substitutes for low temperature treatment?
(a) auxin
(b) gibberellins
(c) cytokinin
(d) none of the above
Answer: (b) gibberellins
13. 2-4-dichlorophenoxyacetic acid is generally used as
(a) fungicide
(b) weedicide
(c) pesticides
(d) growth inhibitor
Answer: (b) weedicide
14. Garner and Allard are related with
(a) photophosphorylation
(b) photoperiodism
(c) phototropism
(d) photolysis
Answer: (b) photoperiodism
15. Which of the following hormones is known to promote maleness in flowering plants?
(a) gibberellic acid
(b) Kinetin
(c) IAA
(d) 2,4 D
Answer: (a) gibberellic acid
16. Cytokinin
(a) is a hormone whose main function is to induce the cell division
(b) is the process of cell division
(c) refers to cell division
(d) causes dormancy
Answer: (a) is a hormone whose main function is to induce the cell division
17. The coleoptile in grass seedling is
(a) radical
(b) plumule
(c) cotyledon
(d) sheath around emerging leaf
Answer: (d) sheath around emerging leaf
18. Abscisic acid controls
(a) shoot elongation
(b) cell elongation and cell wall formation
(c) cell division
(d) leaf fall and dormancy
Answer: (d) leaf fall and dormancy
19. Highest concentration of auxin exists
(a) at the base of various plant organs
(b) in growing tips of plants
(c) in leaves
(d) in xylem and phloem cells only
Answer: (b) in growing tips of plants
20. An excised leaf does not turn yellow if it is induced to root. This is attributed to the synthesis in the root of
(a) ethylene
(b) cytokinins
(c) gibberellins
(d) auxins
Answer: (b) cytokinins
21. The ripening of fruit can be hastened by treatment with
(a) gibberellic acid
(b) indole acetic acid
(c) florigen
(d) ethylene gas
Answer: (d) ethylene gas
22. Indole 3 Acetic Acid, called auxin was first isolated from
(a) human urine
(b) corn germ oil
(c) fusarium
(d) rhizopus
Answer: (a) human urine
23. Primary precursor of IAA is
(a) phenylalanine
(b) tyrosine
(c) tryptophan
(d) lucine
Answer: (c) tryptophan
24. In higher plants the reason for effective apical growth
(a) photoperiodism
(b) enzyme
(c) hormones
(d) requirement of light
Answer: (c) hormones
25. The growth regulator that retards ageing of plant organ is
(a) auxin
(b) gibberellins
(c) cytokinin
(d) abscisic acid
Answer: (c) cytokinin
26. In plants auxin synthesis occurs in
(a) cortex
(b) phloem cells
(c) root and shoot tips
(d) xylem cells
Answer: (c) root and shoot tips
27. Apical dominance is caused by
(a) auxin
(b) gibberellins
(c) Kinetin
(d) ABA
Answer: (a) auxin
28. Hormone used in early ripening of fruit is
(a) auxin
(b) ABA
(c) ethylene gas
(d) cytokinin
Answer: (c) ethylene gas
29. Induction of cell division and delay in senescence is due to
(a) cytokinin
(b) Kinetin
(c) gibberellins
(d) auxin
Answer: (a) cytokinin
30. Which of the following is the effect of 2,4 di chlorophenoxy acetic acid?
(a) increase of branches
(b) increase in the growth of all parts
(c) delay in senescence
(d) bolting
Answer: (b) increase in the growth of all parts
31. Which of the following inhibits the growth of lateral axillary buds?
(a) ethylene
(b) auxin
(c) gibberellins
(d) cytokinin
Answer: (b) auxin
32. Which of the following induces flowering in short day plants?
(a) gibberellins
(b) cytokinins
(c) auxin
(d) abscissic acid
Answer: (a) gibberellins
33. Which of the following is caused by gibberellins?
(a) rooting
(b) bolting
(c) epinasty
(d) fruit ripening
Answer: (b) bolting
34. What are morphactins?
(a) auxins
(b) natural growth regulators
(c) synthetic growth regulators
(d) metabolic inhibitors
Answer: (c) synthetic growth regulators
35. Auxins can be synthesized from
(a) tryptophan
(b) pyruvic acid
(c) glycogen
(d) none of the above
Answer: (a) tryptophan
36. Germination of seeds is prevented by
(a) auxins
(b) gibberellins
(c) cytokinin
(d) dormin
Answer: (d) dormin
37. Auxin and ethylene promote
(a) flowering in litchi and pineapple
(b) synchronous flowering in pineapple
(c) increase flowering in cucumbers
(d) all of these
Answer: (d) all of these
38. Hormone causing an apical dominance
(a) auxin
(b) ethylene
(c) gibberellins
(d) all the above
Answer: (a) auxin
39. Flowering is controlled by the length of light period due to the presence of the pigment
(a) chlorophyll
(b) carotenoid
(c) phytochrome
(d) xanthophylls
Answer: (c) phytochrome
40. Cut leaves can remain green longer if dipped in a solution of
(a) gibberellins
(b) cytokinin
(c) auxin
(d) ethylene
Answer: (b) cytokinin
41. Which of the following induces cell division?
(a) cytokinins
(b) gibberellins
(c) auxins
(d) abscisic acid
Answer: (a) cytokinins
42. Leaf fall occurs when the content of
(a) auxin decreases
(b) cytokinin increases
(c) gibberellic acid decreases
(d) abscisic acid decreases
Answer: (a) auxin decreases
43. Femaleness is induced in plants by
(a) gibberellins
(b) cytokinins
(c) auxin
(d) abscisic acid
Answer: (c) auxin
44. A marked increase in stem length is by
(a) GA
(b) IAA
(c) Florigen
(d) Vernalin
Answer: (a) GA
45. Exponential growth occurs in
(a) Yeast
(b) Bacteria
(c) Asexual reproduction
(d) All of these
Answer: (c) Asexual reproduction
46. Leaf abscission is caused by
(a) ABA
(b) Cytokinin
(c) Auxin
(d) Gibberellin
Answer: (a) ABA
47. Which one of the following breaks dormancy of potato tuber?
(a) Gibberellin
(b) IAA
(c) ABA
(d) Zeatin
Answer: (a) Gibberellin
48. Mobilization of stored food in germinating seed is triggered by?
(a) GA
(b) IAA
(c) Morphactin
(d) None of these
Answer: (a) GA
49. 2,4 D is
(a) weedicide
(b) insecticide
(c) rodenticide
(d) nematicide
Answer: (a) weedicide
50. Cell volume increases due to
(a) auxin
(b) gibberellins
(c) cytokinins
(d) ethylene
Answer: (a) auxin