Question

Auxins : Apical dominance : : Gibberellins : .............

• A. Adventitious shoot formation
• B. Accelerates abscission
• C. Closure of stomata
• D. Bolting

Hint:

Bolting is often triggered by exposure to long days or cold temperatures.

Answer 1

The Correct Option is D

Complete the analogy:

Auxins : Apical dominance :: Gibberellins : Bolting

(A) Adventitious shoot formation - Incorrect: This is primarily controlled by cytokinins, not gibberellins.

(B) Accelerates abscission - Incorrect: Abscission is regulated by ethylene and inhibited by auxins.

(C) Closure of stomata - Incorrect: Stomatal closure is mediated by abscisic acid (ABA).

(D) Bolting - Correct: Gibberellins induce bolting (rapid stem elongation) in rosette plants before flowering.

The correct answer is (D) Bolting, as gibberellins are well-known for promoting this dramatic stem growth response.

Answer 2

Auxins are plant hormones involved in a variety of growth and developmental processes. One of their key roles is in regulating apical dominance.

Apical dominance is a phenomenon where the growth of the main (apical) stem inhibits the growth of lateral (side) shoots. This is primarily because the auxins produced at the apex (top) of the plant inhibit the growth of lateral buds.

Gibberellins, another class of plant hormones, promote growth processes, particularly the elongation of stems and the initiation of flowering. One specific effect of gibberellins is bolting.

Bolting is the rapid elongation of the stem, which is often seen in plants like lettuce and cabbage when they are exposed to gibberellins.

Gibberellins promote flowering in some plants, and bolting is a key feature in the transition from vegetative growth to flowering, especially in certain crops like cabbage, spinach, and lettuce.

Thus, the correct analogy is Auxins: Apical Dominance :: Gibberellins: Bolting.