Question

Plant hormones regulate growth and development. Select the correct statements with reference to them.
A. Auxins regulate fruit ripening
B. Cytokinins promote cell differentiation and division
C. Gibberellins stimulate elongation in dwarf plants
D. Abscisic acid regulates seed dormancy and germition

• A. A and D Only
• B. B, C and D Only
• C. A, B and C Only
• D. B, A and D Only

Hint:

Phytohormone Roles:
Fruit Ripening = Ethylene (NOT Auxin!).
Cell Division = Cytokinins.
Overcoming Dwarfism = Gibberellins.
Seed Dormancy = Abscisic Acid (ABA).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question requires identifying the scientifically accurate functiol roles of plant hormones (phytohormones) among the given statements.

Step 2: Key Formula or Approach:
Review major phytohormone functions:
• Ethylene: Gaseous hormone primarily responsible for fruit ripening.

• Auxin: Promotes cell elongation, apical domince, and root initiation.

• Cytokinin: Promotes cell division (cytokinesis) and shoot differentiation.

• Gibberellin: Promotes stem bolting/internode elongation, breaking dwarfism.

• Abscisic Acid (ABA): Enforces seed dormancy, stress tolerance, and inhibits premature germition.

Step 3: Detailed Explation:

• Statement A (False): Fruit ripening is regulated primarily by the gaseous hormone Ethylene, not Auxin. Auxin prevents pre-harvest fruit drop and promotes fruit set, but does not trigger ripening.

• Statement B (True): Cytokinins stimulate cytokinesis (cell division) and work in concert with auxins to promote cell differentiation and shoot morphogenesis.

• Statement C (True): Gibberellins ($\text{GA}_3$) promote internodal cell elongation, overcoming genetic dwarfism in plants like dwarf maize and peas.

• Statement D (True): Abscisic acid (ABA) acts as a growth inhibitor, establishing and maintaining seed dormancy until favorable conditions arise.

Step 4: Fil Answer:
Statements B, C, and D are correct, corresponding to Option (B).