Short answerModerate1 mark
3(ii)
Ramesh is a farmer who has a vineyard and cultivates grapes. To improve the shape of the grapes and make them elongated he sprays a particular phytohormone at the time of fruiting.
Name the phytohormone that Ramesh sprays on the plant at the time of fruiting.
Topic: Gibberellin
Previous-year question practice database
Answer
Exam answer
GIBBERELLIN (gibberellic acid).
Explanation
Gibberellin causes ELONGATION of cells, which is exactly what the grower wants — longer, larger grapes. It is used commercially on seedless varieties for this purpose.
The four plant hormones, each by its chief effect: AUXIN — cell elongation in shoots; controls tropisms GIBBERELLIN — stem and fruit elongation; breaks seed dormancy CYTOKININ — promotes cell DIVISION ABSCISIC ACID — the stress hormone; closes stomata, causes dormancy and leaf fall
More from Chemical Coordination in Plants
Assertion (A): Abscisic acid promotes stomatal closure during a drought.
Reason (R): Abscisic acid helps the plant to conserve water during stress.2026The tropic movement wherein the tendrils of a pea plant twine around a support.2026Auxin, Oxytocin, Gibberellin, Cytokinin2026Sunil tried to match the tropic movements in plants with the stimulus they respond to. The tabulation is given below:
P. Thigmotropism — Touch
Q. Geotropism — Water
R. Chemotropism — Chemicals
S. Phototropism — Gravity
Identify the correct pair:2025These grapes are said to be seedless. What is the technical term for the formation of such fruits?2025The tropic movement of plant parts in response to chemicals.2024