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Class 11 Biology Chapter 15 MCQs with Answers and Ads


Class 11 Biology Chapter 15: Plant Growth and Development – 100 MCQs with Answers



1. The hormone promoting cell enlargement is:

A) Auxin
B) Gibberellin
C) Cytokinin
D) Ethylene
Answer: B) Gibberellin
2. The site of perception of photoperiod is:

A) Flower
B) Leaf
C) Stem
D) Root
Answer: B) Leaf
3. Vernalisation induces:

A) Seed germination
B) Flowering
C) Dormancy
D) Growth
Answer: B) Flowering
4. The most abundant plant hormone is:

A) Auxin
B) Cytokinin
C) Ethylene
D) Abscisic acid
Answer: A) Auxin
5. The process of losing ability to divide is called:

A) Dedifferentiation
B) Redifferentiation
C) Differentiation
D) Senescence
Answer: C) Differentiation
6. The hormone responsible for apical dominance:

A) Cytokinin
B) Auxin
C) Gibberellin
D) ABA
Answer: B) Auxin
7. Bolting in plants is induced by:

A) Ethylene
B) Auxin
C) Cytokinin
D) Gibberellin
Answer: D) Gibberellin
8. Short day plants require:

A) Long photoperiod
B) Short photoperiod
C) Continuous light
D) Light and darkness
Answer: B) Short photoperiod
9. Which plant part is the main site for ABA synthesis?

A) Root
B) Leaf
C) Stem
D) Seed
Answer: B) Leaf
10. The natural gaseous plant hormone is:

A) Ethylene
B) Gibberellin
C) Auxin
D) Cytokinin
Answer: A) Ethylene



11. The hormone responsible for fruit ripening is:

A) Auxin
B) Ethylene
C) Gibberellin
D) Cytokinin
Answer: B) Ethylene
12. The phase where no visible growth takes place:

A) Lag phase
B) Log phase
C) Stationary phase
D) Decline phase
Answer: A) Lag phase
13. Pruning promotes branching due to:

A) Removal of auxin
B) Retardation of cytokinins
C) Inhibition of ABA
D) Promotion of gibberellins
Answer: A) Removal of auxin
14. Which event marks the onset of seed dormancy in plants?

A) Increased gibberellin
B) High auxin
C) Increased ABA
D) Increased IAA
Answer: C) Increased ABA
15. ‘Grand period of growth’ refers to:

A) Lag phase
B) Log phase
C) Stationary phase
D) Dormant phase
Answer: B) Log phase
16. The process of re-gaining the capability of cell division is:

A) Differentiation
B) Dedifferentiation
C) Redifferentiation
D) Elongation
Answer: B) Dedifferentiation
17. Which hormone breaks seed dormancy?

A) ABA
B) Ethylene
C) Gibberellin
D) IAA
Answer: C) Gibberellin
18. Parthenocarpy can be induced by:

A) IAA
B) ABA
C) Ethylene
D) Cytokinin
Answer: A) IAA
19. Growth in plants is:

A) Open
B) Closed
C) Finite
D) None
Answer: A) Open
20. Auxins are produced in:

A) Shoot tips
B) Root tips
C) Leaves
D) Flowers
Answer: A) Shoot tips



21. Growth rate is highest during:

A) Lag phase
B) Log phase
C) Stationary phase
D) Senescence
Answer: B) Log phase
22. Which hormone inhibits growth:

A) Gibberellin
B) Ethylene
C) ABA
D) Cytokinin
Answer: C) ABA
23. Apical dominance can be overcome by:

A) Removing shoot apex
B) Removing root tip
C) Increasing auxin
D) Decreasing cytokinin
Answer: A) Removing shoot apex
24. The hormone discovered from fungus is:

A) Auxin
B) GA (Gibberellin)
C) Cytokinin
D) ABA
Answer: B) GA (Gibberellin)
25. Which phase comes after elongation?

A) Cell division
B) Maturation
C) Dormant
D) Resting
Answer: B) Maturation
26. Ethylene is synthesized from:

A) Methionine
B) Tryptophan
C) GA
D) ABA
Answer: A) Methionine
27. Which hormone is used to ripen mangoes commercially?

A) Gibberellin
B) Cytokinin
C) Ethylene
D) ABA
Answer: C) Ethylene
28. Which process is promoted by light in plants?

A) Etiolation
B) Photomorphogenesis
C) Scattering
D) Bolting
Answer: B) Photomorphogenesis
29. Which is called ‘stress hormone’ in plants?

A) Gibberellin
B) ABA
C) Ethylene
D) Auxin
Answer: B) ABA
30. Gibberellins were discovered in:

A) Fungi
B) Algae
C) Bacteria
D) Lichens
Answer: A) Fungi



31. In which organ is photoperiod measured first?

A) Root
B) Leaf
C) Shoot
D) Flower
Answer: B) Leaf
32. Cell enlargement is largely attributed to:

A) ABA
B) Water uptake
C) Cytokinin
D) IAA
Answer: B) Water uptake
33. Which is a natural auxin?

A) IBA
B) NAA
C) IAA
D) 2,4-D
Answer: C) IAA
34. Vernalization effect is seen in:

A) Wheat
B) Potato
C) Onion
D) Ginger
Answer: A) Wheat
35. Which hormone promotes stomatal closure under stress?

A) ABA
B) GA
C) IAA
D) Cytokinin
Answer: A) ABA
36. Somatic embryogenesis is induced by:

A) Abscisic acid
B) Cytokinin
C) 2,4-D
D) Ethylene
Answer: C) 2,4-D
37. Growth curve of plants is:

A) Sigmoid
B) Linear
C) Parabolic
D) Exponential
Answer: A) Sigmoid
38. The hormone that stimulates root formation in cuttings:

A) Cytokinin
B) Auxin
C) Gibberellin
D) ABA
Answer: B) Auxin
39. Dormancy of seeds is due to:

A) IAA
B) ABA
C) Cytokinin
D) Gibberellin
Answer: B) ABA
40. Which is responsible for geotropism in roots?

A) Gibberellin
B) Cytokinin
C) Auxin
D) ABA
Answer: C) Auxin



41. Cytokinins were first isolated from:

A) Yeast
B) Coconut milk
C) Corn kernels
D) Tomato
Answer: B) Coconut milk
42. Which hormone delays leaf senescence?

A) Cytokinin
B) ABA
C) GA
D) Auxin
Answer: A) Cytokinin
43. Which induces parthenocarpy?

A) IAA
B) ABA
C) Cytokinin
D) GA
Answer: A) IAA
44. A cell that loses its ability to divide and matures is:

A) Meristematic
B) Redifferentiated
C) Dedifferentiated
D) Elongated
Answer: B) Redifferentiated
45. Stomata open due to:

A) Loss of water
B) Turgor pressure increase in guard cells
C) ABA
D) Ethylene
Answer: B) Turgor pressure increase in guard cells
46. Apical meristem produces:

A) Leaves
B) Stems
C) Flowers
D) All above
Answer: D) All above
47. Which is not a plant growth hormone?

A) Auxin
B) GA
C) ABA
D) Amylase
Answer: D) Amylase
48. Climacteric rise of respiration is found in:

A) Ripening fruit
B) Seed
C) Root
D) Bud
Answer: A) Ripening fruit
49. Annual ring in wood shows:

A) Primary growth
B) Secondary growth
C) Apical dominance
D) Dormancy
Answer: B) Secondary growth
50. The plant response to light duration is called:

A) Photoperiodism
B) Vernalisation
C) Bolting
D) Epinasty
Answer: A) Photoperiodism



51. Growth in length occurs by:

A) Apical meristem
B) Lateral meristem
C) Intercalary meristem
D) All above
Answer: A) Apical meristem
52. Which is an inhibitor of seed germination?

A) Gibberellin
B) Auxin
C) ABA
D) Cytokinin
Answer: C) ABA
53. Abscission of leaves is promoted by:

A) IAA
B) Cytokinin
C) ABA
D) Ethylene
Answer: D) Ethylene
54. Which phase follows steepest slope in a growth curve?

A) Lag
B) Log
C) Stationary
D) Senescence
Answer: C) Stationary
55. Hormone involved in dormancy:

A) IAA
B) Cytokinin
C) ABA
D) Gibberellin
Answer: C) ABA
56. 2,4-D is used as:

A) Herbicide
B) Growth inhibitor
C) Ripening agent
D) Alkaloid
Answer: A) Herbicide
57. Red light promotes:

A) Germination
B) Dormancy
C) Senescence
D) Abscission
Answer: A) Germination
58. Maximum growth is observed in:

A) Seedling
B) Mature leaf
C) Dormant seed
D) Old root
Answer: A) Seedling
59. Cytokinins are synthesized in:

A) Root tip
B) Shoot tip
C) Leaf
D) Stem
Answer: A) Root tip
60. Which is not a role of auxin?

A) Cell elongation
B) Root initiation
C) Flower induction
D) Fruit growth
Answer: C) Flower induction



61. ABA was first isolated from:

A) Tobacco
B) Potato
C) Maize
D) Rice
Answer: C) Maize
62. Photoperiodic stimulus is perceived by:

A) Root
B) Stem
C) Leaf
D) Bud
Answer: C) Leaf
63. Which plant hormone induces fruit ripening:

A) Ethylene
B) ABA
C) GA
D) Cytokinin
Answer: A) Ethylene
64. Which is not a function of cytokinins?

A) Cell division
B) Delay senescence
C) Promote shoot formation
D) Promote apical dominance
Answer: D) Promote apical dominance
65. Hormone used as weed killer:

A) NAA
B) 2,4-D
C) IAA
D) Cytokinin
Answer: B) 2,4-D
66. The type of growth shown by root tip:

A) Open
B) Closed
C) Linear
D) Determinate
Answer: A) Open
67. Who discovered gibberellins?

A) Went
B) Kurosawa
C) Miller
D) Skoog
Answer: B) Kurosawa
68. Which hormone regulates photoperiodism?

A) ABA
B) Phytochrome
C) IAA
D) GA
Answer: B) Phytochrome
69. Which hormone prevents leaf abscission:

A) ABA
B) Ethylene
C) Auxin
D) GA
Answer: C) Auxin
70. Which is responsible for senescence?

A) Cyotokinin
B) Gibberellin
C) ABA
D) NAA
Answer: C) ABA



71. Which is the site for secondary growth in plants?

A) Apical meristem
B) Lateral meristem
C) Root cap
D) Intercalary meristem
Answer: B) Lateral meristem
72. Growth in diameter of stem occurs due to:

A) Cambium
B) Apical meristem
C) Root cap
D) Protoderm
Answer: A) Cambium
73. Which hormone is related to photoperiodism?

A) ABA
B) Phytochrome
C) GA
D) Ethylene
Answer: B) Phytochrome
74. Etiolation refers to:

A) Rapid stem elongation
B) Short stem
C) Short root
D) Excessive flowering
Answer: A) Rapid stem elongation
75. Flowering in some plants needs exposure to:

A) High temp
B) Low temp
C) Water
D) Light
Answer: B) Low temp
76. Vernalization is required by:

A) Annuals
B) Biennials
C) Perennials
D) Ephemerals
Answer: B) Biennials
77. Which is not a plant growth regulator?

A) ABA
B) GA3
C) ATP
D) 2,4-D
Answer: C) ATP
78. An example of long day plant:

A) Wheat
B) Rice
C) Cotton
D) Potato
Answer: A) Wheat
79. In fruit ripening, which hormone increases respiration:

A) GA
B) ABA
C) Cytokinin
D) Ethylene
Answer: D) Ethylene
80. Apical dominance results in:

A) Lateral branching
B) Vertical growth
C) Root initiation
D) Leaf growth
Answer: B) Vertical growth



81. Growth curve is:

A) Linear
B) S-shaped
C) Exponential
D) Bell-shaped
Answer: B) S-shaped
82. Cytokinins promote:

A) Cell elongation
B) Cell division
C) Leaf fall
D) Senescence
Answer: B) Cell division
83. Phytochrome exists in:

A) Two forms
B) Three forms
C) One form
D) Many forms
Answer: A) Two forms
84. The carbohydrate storing region in embryo:

A) Scutellum
B) Plumule
C) Hypocotyl
D) Endosperm
Answer: D) Endosperm
85. Which promotes the movement of nutrients from old to young leaves:

A) Cytokinins
B) Auxin
C) ABA
D) Ethylene
Answer: A) Cytokinins
86. Which hormone increases during stress?

A) ABA
B) Ethylene
C) Auxin
D) GA
Answer: A) ABA
87. Which light inhibits hypocotyl elongation?

A) Red
B) Blue
C) Green
D) Far-red
Answer: A) Red
88. Phytochrome is present in:

A) All plant cells
B) Only leaf cells
C) Only root cells
D) Only shoot apex
Answer: A) All plant cells
89. Endogenous dormancy refers to:

A) Imposed by embryo
B) By seed coat
C) By environment
D) None
Answer: A) Imposed by embryo
90. ABA acts as:

A) Inhibitor
B) Promoter
C) Both
D) Neutral
Answer: A) Inhibitor



91. ABA was formerly called:

A) Dormin
B) Ripenin
C) Gibb
D) None
Answer: A) Dormin
92. Growth whose rate is proportional to size:

A) Arithmetic
B) Geometric
C) Logarithmic
D) Negative
Answer: B) Geometric
93. Callus formation in tissue culture needs:

A) IAA
B) NAA
C) Cytokinin
D) Both auxin & cytokinin
Answer: D) Both auxin & cytokinin
94. Endogenous hormones are:

A) Made inside
B) Supplied outside
C) Imported
D) Synthetic
Answer: A) Made inside
95. Seed dormancy is broken naturally by:

A) Passage of time
B) Scarification
C) Frost
D) None
Answer: A) Passage of time
96. Who demonstrated root formation with auxin?

A) Skoog & Miller
B) Kurosawa
C) Darwin
D) Miller & Went
Answer: A) Skoog & Miller
97. Plant growth is:

A) Irreversible
B) Reversible
C) Temporary
D) None
Answer: A) Irreversible
98. Dormancy in potato tuber is broken by:

A) Cytokinin
B) GA
C) ABA
D) IAA
Answer: B) GA
99. Etiolation is a result of:

A) Dark
B) Crowding
C) High light
D) Lack of roots
Answer: A) Dark
100. Which phase of growth is absent in determinate organs?

A) Lag
B) Log
C) Stationary
D) All present
Answer: C) Stationary

End of MCQ List.
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