Question

Abscisic acid controls
A) Cell division
B) Leaf fall and dormancy
C) Shoot elongation
D) Cell elongation and wall formation

Answer 1

Hint:Abscisic acid is a plant growth regulator also known as phytohormones or plant hormones which is a simple and small molecule derived from carotenoids.

Complete answer
-Abscisic acid plays a very important role in overall plant growth and development.
-The main function of abscisic acid in the plant is the regulation of dormancy and abscission (Detachment of leaves or other parts of plant).
-Abscisic acid induces dormancy in the plant so that seeds can remain unaffected by factors that are unfavorable for plant growth.

Option(A): Cell division in plants is promoted by a plant growth regulator known as Auxin, Therefore this is an Incorrect option.
Option(B): Abscisic acid is responsible for leaf fall and dormancy, Therefore this is the Correct option.
Option(C): Shoot elongation in plants is also promoted by Auxin, Therefore this is an Incorrect option.
Option(D): Cell wall formation and elongation are also controlled by Auxin, Therefore this is an Incorrect option.

Additional Information:
-Abscisic acid is also known as the stress hormone because it inhibits the germination of seed and leads to the closing of stomata so that the plant can withstand unfavorable conditions.
-Abscisic acid is an antagonist of Gibberellic acid because both of them have opposite roles in plants.

Hence the correct answer is option ‘B’.

Note:During the 1960s, three researchers independently researched three different inhibitors known as dormin, inhibitor-B, and abscission-II, Later on, experiments were conducted which concluded that all three of them have the same chemical structure and they were together named Abscisic acid (ABA).