Which one of the following pairs, is not correctly matched?
- Gibberellic acid - Leaf fall
- Cytokinin - Cell division
- IAA - Cell wall elongation
- Abscisic acid - Stomatal closure
Answer
(1) Gibberellic acid - Leaf fall
Solution
As per NCERT:
Cytokinins promote cell division (cytokinesis) – correctly matched.
Auxins (IAA) cause cell elongation / cell wall loosening – correctly matched.
Abscisic acid (ABA) stimulates closure of stomata – correctly matched.
Gibberellins cause stem elongation, bolting and delay senescence; leaf fall (abscission) is promoted by ABA and ethylene, not by gibberellic acid.
∴ Gibberellic acid – Leaf fall is not correctly matched.
Answer: (1)