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 kind of a plant growth regulator also known as phytohormones or plant hormones that controls the growth of the plants and it is a simple and small molecule obtained from carotenoids.

Complete answer:
Abscisic acid plays a very essential role in overall plant growth and development.
1)The main function that is performed by the abscisic acid in the plant is the regulation of dormancy and abscission (Detachment of leaves or other parts of plant).
2)Abscisic acid induces and stimulates the dormancy in the plant so that seeds can remain unaffected by some points and factors that are unfavourable for plant growth.

Now let us find solution from given options:
Option(A): Cell division in plants is stimulated and increased by a plant growth regulator known as Auxin, therefore this option is not correct.
Option(B): Abscisic acid is responsible and needed for leaf fall and dormancy, Therefore this is the exactly Correct option.
Option(C): Shoot elongation in plants is also promoted and increased by the effect Auxin, Therefore this is not a correct option.
Option(D): Cell wall formation and elongation are also the functions performed by Auxin, Therefore this is also an Incorrect option.

Hence, the correct answer is option (B)

Note: During the 1960s, three researchers on behalf of themselves researched three different inhibitors known as dormin, inhibitor-B, and abscission-l1, later on, experiments were performed which concluded that all three of them have the same chemical structure and they were together named Abscisic acid (ABA).