NEET BIOLOGY

Detailed explanation-1: -These chemicals are known as anti-transpirants. There are two common examples of anti-transpirants are abscisic acid (ABA) and Phenyl mercuric acetate (PMA). They act by the partial closing of the stomata to decrease the rate of transpiration.

Detailed explanation-2: -> Option D: Phenyl mercuric acetate: It is an anti transpirant chemical used to reduce the transpiration rate and also the number of stomata. Hence, the correct answer is option (D).

Detailed explanation-3: -During stress, a plant hormone, that is, ABA or abscisic acid, which is a plant growth regulator encourages the closure of stomata. This closing of stomata diminishes the rate of transpiration and enhances the water stress resistance capacity of the plant. Thus, ABA is considered the antitranspirant hormone.

Detailed explanation-4: -By promoting closure of stomata (by affecting the guard cells around the stomatal pore), thus decreasing the loss of water vapours from the leaf.

Detailed explanation-5: -Antitranspirants are compounds applied to the leaves of plants to reduce transpiration. They are used on Christmas trees, on cut flowers, on newly transplanted shrubs, and in other applications to preserve and protect plants from drying out too quickly.