Question

Which of the following breaks the dormancy of a potato tuber?
(a) Gibberellin
(b) Indole acetic acid
(c) Abscisic acid
(d) Zeatin

Answer 1

Hint: The dormant state of a plant is a state in which it is inactive or the metabolic activity of the plant is reduced to a very low rate. To break the dormancy of the plant produces certain hormones. The dormancy can be easily seen in the seeds.

Complete answer:
The dormancy of the potato tuber is broken by the gibberellin. This hormone is usually present in very small quantities but is useful for breaking the dormancy. It is also used in the seed germination of the plants. In the potato tubers, the gibberellin hormone helps in the elongation of the plantlets from the tubers. These tubers are generally present in a dormant state but after some time in favorable conditions, the plantlets arise from the tubers.
Seed dormancy can be caused due to physiological conditions and chemical conditions of the seeds. The hormone which is responsible for seed dormancy is abscisic acid. It maintains the seed dormancy state and is the only plant hormone to do so. Bud dormancy is also controlled by abscisic acid. This hormone sends stimulation to go into a dormant state when the plant approaches the winter season. Abscisic acid helps the plant to lower the metabolic activity in order to protect the buds and seeds during the cold winter season.

So, the correct answer is ‘gibberellin’.

Note:
The dormancy of a plant or seed is a condition in which the plant may stop its metabolic activity completely or it may reduce its metabolic activity. The abscisic acid promotes the dormancy of the plants whereas gibberellin breaks the dormancy of the plant.