Opening and closing of the stomata:
A) occur during prolonged periods of drought.
B) occur when there is a high concentration of carbon dioxide in the leaf.
C) are under hormonal control.
D) are triggered by darkness.
E) are controlled by the changes in shape of the companion cells.

Question

Quizplus · Accepted Answer

The opening and closing of stomata are primarily regulated by the hormone abscisic acid, which responds to environmental conditions such as light, carbon dioxide concentration, and water availability.

Opening and Closing of the Stomata