Q.41 Which of the following combinations of plant hormones and their associated
function are CORRECT?
Hormone Function
P. Abscisic acid Breaks seed dormancy
Q. Auxin Induces cell division
R. Ethylene Stimulates ripening of fruits
S. Gibberellin Promotes seed dormancy
(A) P and R only
(B) P and S only
(C) Q and R only
(D) Q and S only
The accurate combination of plant hormones and their functions involves auxin inducing cell division and ethylene stimulating fruit ripening. This multiple-choice question tests knowledge of plant physiology, relevant for exams like NEET or CSIR NET in biological sciences.
Option Analysis
Abscisic acid (P) induces seed dormancy and stomatal closure during stress, not breaking dormancy; gibberellins handle that role. Thus, P is incorrect.
Auxin (Q) primarily promotes cell elongation but also induces division in vascular tissues and lateral roots through auxin-cytokinin interactions.
Ethylene (R) is the ripening hormone, accelerating climacteric fruit softening, color change, and enzyme activation like pectinase.
Gibberellin (S) breaks seed dormancy by mobilizing reserves and elongating aleurone cells, not promoting it; abscisic acid does.
| Option | Hormones | Correct? | Reason |
|---|---|---|---|
| A: P & R | Abscisic acid, Ethylene | No | P wrong (induces dormancy) |
| B: P & S | Abscisic acid, Gibberellin | No | Both inverted (S breaks dormancy) |
| C: Q & R | Auxin, Ethylene | Yes | Q induces division; R ripens fruits |
| D: Q & S | Auxin, Gibberellin | No | S promotes germination, not dormancy |
Exam Tips
Focus on opposites: ABA vs. gibberellins for dormancy, ethylene for ripening. Auxin synergizes with cytokinin for division, though cytokinin dominates. Review for molecular biology sections in plant biotech.
