Question

Common cause of seed and bud dormancy in the presence of
A) Ethylene
B) Cytokinin
C) Abscisic acid
D) Both B and C

Answer 1

Hint: Dormancy is a state where a particular plant part may stop its metabolic activity completely or may also reduce its metabolic activity. In such a state, they lose the ability to divide, reproduce, and grow in size. The development is halted in such a stage.

Complete answer:
Seed dormancy is a state of the seed when it fails to germinate by itself even in the favorable environmental conditions due to their reduced metabolism. Seed dormancy can be caused due to physiological conditions or may also be caused due to chemical conditions. The hormone which is responsible for the 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 the abscisic acid. This hormone sends stimulation to go into a dormant state when the plant approaches the winter season. It helps the plant to lower the metabolic activity of the seed and bud in order to protect the buds and seeds during the cold winter season.

Additional information: The ethylene hormone is present at very low levels in the plant body. This hormone is used only for the ripening of the fruits. It also helps in regulating the growth of the flower and regulates its opening also. Cytokinin is the hormone that is mainly responsible for the cell division in the plant body.

So, the answer is (C) ‘abscisic acid’.

Note: Abscisic acid is the only hormone present in the plant body that causes the state of dormancy in the seeds and bud. The dormant state lowers the metabolic activity of the seed and bud in order to protect them from the harsh winter season.