Question

____ is an antitranspirant.

Answer 1

Antitranspirant:

1. Antitranspirant is a chemical that is sprinkled on the surfaces of plant leaves and stems to restrict water loss and minimize transpiration.
2. Transpiration is the process of water loss through the stomata of plant leaves.

Examples of Antitranspirants:

1. Abscisic acid (ABA)
2. Phenylmercury acetate
3. Aspirin

Why Abscisic acid is an antitranspirant:

1. The stomata get closed when the guard cells' osmotic pressure decreases nearly to the surrounding cells.
2. ABA can stimulate K⁺ ion outflow from guard cells, resulting in the decrease of osmotic pressure and, finally, stomata closure.
3. As a result, it's referred to as an antitranspirant.

Final Answer: Abscisic acid (ABA) is an antitranspirant.