Question

Identify two of the following phytohormones which regulate the stomatal movements.
(a) IAA
(b) GA
(c) Zeatin
(d) ABA
The correct pair is:

• A. a, c
• B. b, c
• C. c, d
• D. b, d

Answer 1

The correct option is C c, d

The full form of ABA is abscisic acid. It is the best known hormone that helps in the stomatal movement. Stomatal movement is the opening and closing of stomata. When the guard cells are turgid, stomata open and when flaccid, stomata close.

Some other phytohormones, such as brassinosteroids, jasmonic acid, cytokinins like zeatin are also involved in the stomatal movement. Zeatin is the first natural cytokinins that also can promote the growth of lateral buds.

So, the correct answer is "Zeatin and ABA".