A hormone that prevents senescence In leaves is:
Correct answer: B. Cytokinin
- A. Abscisic acid
- B. Cytokinin
- C. Seisomonasty
- D. Demonasty
Explanation
Senescence is the aging of individual cells within an organism. The organism itself is still alive and metabolizing energy, but its cells no longer divide to create new cells, which is necessary for growth and repair. Hence, the individual cells remain alive but in a state of dormancy. Cytokinins are plant hormones that influence growth and the stimulation of cell division. Cytokinins also act in conjunction with auxin (another plant hormone) to retard senescence. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period.
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About Plant Growth Regulators
Plant growth regulators are chemical messengers that control growth, development and responses to the environment. The topic covers auxins, gibberellins, cytokinins, abscisic acid and ethylene, including cell elongation, apical dominance, tropisms, seed germination, dormancy, fruit ripening and leaf fall, with growth promoters distinguished from inhibitors.
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