- Which process is controlled by vernalization in plants?
a) Seed germination
b) Leaf abscission
c) Induction of flowering
d) Root elongation
Answer: c) Induction of flowering
Explanation:
Vernalization is the process in which prolonged exposure to cold temperatures induces flowering in plants, particularly in biennials and winter annuals.
- Which of the following is an effect of cytokinins on plants?
a) Promote cell division
b) Inhibit root growth
c) Promote fruit ripening
d) Stimulate seed dormancy
Answer: a) Promote cell division
Explanation:
Cytokinins promote cell division and are essential for tissue growth and development, particularly in the shoot system.
- Which plant hormone helps in overcoming apical dominance, promoting lateral bud growth?
a) Gibberellin
b) Ethylene
c) Cytokinin
d) Abscisic acid
Answer: c) Cytokinin
Explanation:
Cytokinins promote lateral bud growth by overcoming the inhibitory effect of auxins, thereby reducing apical dominance and encouraging the development of side shoots.
- Which of the following is not a function of auxin?
a) Promoting root initiation
b) Promoting stem elongation
c) Inducing seed dormancy
d) Inhibiting lateral bud growth
Answer: c) Inducing seed dormancy
Explanation:
Auxins promote stem elongation, root initiation, and inhibit lateral bud growth (apical dominance). However, they do not induce seed dormancy; this is primarily a function of abscisic acid.
- Which of the following is an example of a long-day plant?
a) Radish
b) Tobacco
c) Lettuce
d) Rice
Answer: c) Lettuce
Explanation:
Lettuce is a long-day plant that requires longer daylight hours to initiate flowering. These plants usually flower in late spring or early summer when the days are longer.
- Gibberellins are used in the brewing industry to:
a) Stimulate root growth
b) Increase seed germination
c) Promote sugar accumulation in grains
d) Stimulate production of hydrolytic enzymes
Answer: d) Stimulate production of hydrolytic enzymes
Explanation:
In the brewing industry, gibberellins are used to stimulate the production of hydrolytic enzymes like amylase, which break down starch into fermentable sugars during the malting process.
- Which hormone is responsible for the closing of stomata during drought conditions?
a) Gibberellin
b) Auxin
c) Ethylene
d) Abscisic acid
Answer: d) Abscisic acid
Explanation:
Abscisic acid (ABA) is responsible for closing stomata during drought conditions, reducing water loss through transpiration and conserving moisture within the plant.
- Which of the following is a role of ethylene in plant growth?
a) Promote lateral bud growth
b) Delay fruit ripening
c) Promote stem elongation
d) Promote fruit ripening
Answer: d) Promote fruit ripening
Explanation:
Ethylene promotes fruit ripening by regulating various biochemical processes, such as the conversion of starches to sugars, softening of the fruit, and color change.
- Which hormone is used to induce parthenocarpy in plants?
a) Abscisic acid
b) Gibberellin
c) Ethylene
d) Cytokinin
Answer: b) Gibberellin
Explanation:
Gibberellins can induce parthenocarpy, leading to the development of seedless fruits without fertilization. This is commonly applied in crops like grapes and tomatoes.
- Which hormone is primarily responsible for inhibiting seed germination during unfavorable conditions?
a) Gibberellin
b) Auxin
c) Abscisic acid
d) Cytokinin
Answer: c) Abscisic acid
Explanation:
Abscisic acid (ABA) inhibits seed germination by inducing seed dormancy during unfavorable conditions, such as drought, ensuring the seed remains viable until conditions improve.
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