Question

Phenyl mercuric acetate

• A. Reduces transpiration rate
• B. Reduces photosynthesis
• C. Kills the plant
• D. Reduces respiration

Answer 1

Answer: (A)

Phenylmercury acetate (PMA) is an organomercury compound used as a fungicide. When applied to the leaves of plants, it is an antitranspirant. PMA functions as an antitranspirant when it is applied directly to the leaves of a plant. It reduces the amount of water lost through transpiration by closing the plant’s stomata. PMA induces stomatal closure at low concentrations of short duration. Prolonged contact will eventually kill the guard cells surrounding the stoma, causing the pores to reopen. PMA does not reduces photosynthesis, reduce respiration or kill plant. Thus, option A is correct.