Question

What is the role of Gibberellic acid in plants?

• A. It promotes cell division and elongation in stem tissues.
• B. It increases the levels of anti-oxidants
• C. It decreases the levels of plant growth hormones.
• D. It inhibits the synthesis of plant secondary metabolites.

Hint:

Associate each major plant hormone with its "headline" function:

\textbf{Auxin:} Apical dominance, tropisms, cell elongation.
\textbf{Gibberellin:} Stem elongation, seed germination.
\textbf{Cytokinin:} Cell division (cytokinesis), anti-aging.
\textbf{Abscisic Acid (ABA):} Dormancy, stress response (stomata closure).
\textbf{Ethylene:} Fruit ripening, senescence.

Answer 1

The Correct Option is A

Step 1: Concept Overview:
The question focuses on the main function of Gibberellic Acid (GA), a major plant hormone.
Step 2: Detailed Explanation:
Gibberellins are plant hormones known for their impact on growth and development.

Stem Elongation: GA significantly stimulates internode lengthening, especially in dwarf plants, by boosting both cell division in the apical meristem and subsequent cell expansion.
Seed Germination: GAs end seed dormancy and enhance germination by triggering hydrolytic enzyme (like \(\alpha\)-amylase) production in cereal grain aleurone layers.
Flowering and Fruit Development: GAs can trigger flowering in some plants (bolting in long-day plants) and participate in fruit development.
Evaluating the options:

(A) It promotes cell division and elongation in stem tissues: This accurately reflects how gibberellins elongate stems.
(B) It increases the levels of anti-oxidants: While hormones influence stress responses, this isn't a primary GA function.
(C) It decreases the levels of plant growth hormones: GA is a major growth hormone, often working with auxins. This is incorrect.
(D) It inhibits the synthesis of plant secondary metabolites: Incorrect. Gibberellin biosynthesis is complex, and its impact on other secondary metabolites varies.
Step 3: Conclusion:
The primary role of Gibberellic acid from the given options is promoting cell division and stem elongation.