Question

Which of these statements is true

• A. ABA opens stomata.
• B. ABA opens stomata while cytokinin closes stomata.
• C. ABA closes while cytokinin opens stomata.
• D. ABA and cytokinin do not affect stomata.

Answer 1

The correct option is C ABA closes while cytokinin opens stomata.

Abscisic acid is an antitranspirant and induces seed dormancy. It helps in the closure of stomata which reduces transpiration. It curtails the stress in plants by inducing stomatal closure. When the rate of transpiration increases more than that of the available water, the plant undergoes stress and in order to prevent the plant from wilting the ABA acts as antitranspirant and closes the stomata.

Cytokinin acts antagonist to ABA and opens the stomata when the plants regain after the stress created due to excessive transpiration and the amount of water available for absorption exceeds the amount of water lost by transpiration.

So, the correct answer is option C.