Which one of the following plant hormones promotes stomatal closure during drought stress?
Abscisic acid
Auxin primarily regulates cell elongation and tropic growth; cytokinin promotes cell division and delays senescence; gibberellin promotes stem elongation, seed germination and flowering — none of these primarily controls stomatal closure under stress.
Abscisic acid (ABA) is known as the "stress hormone" of plants: under drought conditions it accumulates in leaves and triggers guard cells to lose turgor pressure, closing the stomata to reduce water loss through transpiration.
Hence, the answer is Abscisic acid.
Which one of the following statements about the catalytic conversion of nitrogen gas by nitrogenase enzyme in root nodules of leguminous plants is not correct?
Which one of the following statements about xylem vessels in plants is not correct?
Which of the following is a type of nutrition?
I. Heterotrophic
II. Autotrophic
Part of N 2cycle that is opposed to N 2fixation is:
Which among the following is the reproductive part of a plant?
Fibres (Adventitious) roots are found in :
In which Part of the flower does Meiosis take place ?