Question

An antitranspirant is
A. Cobalt chloride
B. Mercury
C. Potassium
D. Phenyl mercuric acetate

Answer 1

Hint: The loss of water from the human body makes our body cool down. In the plants, the evaporation of water occurs via transpiration to escape the excess water. This will help them to maintain the osmotic pressure in the leaves.

Complete answer:
Transpiration is the process by which the plant loses their excess water to the environment. Sometimes this loss can increase excessively which is not desired. So we use the chemicals called the antitranspirants. These compounds will decrease the transpiration rate and also the number of stomata on the leaves.

> Option A: Cobalt chloride: Cobalt helps the plants to reduce the rate of senescence of leaves, it helps them to survive in the drought period.

> Option B: Mercury: It is found in the roots of plants. It is toxic to the plants so the root is the barrier for the uptake of mercury from the soil.

> Option C: Potassium: Potassium helps in the transport of water and minerals in the plant system. It activates various enzymes to alter ATP and protein metabolism.

> 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).

Note: The antitranspirants will save the crops to get marginal yield. This will be helpful in horticulture. When the water costs are very high, then these chemicals play a vital role. PMA-phenylmercuric acetate will also decrease the photosynthetic rate in leaves and also their growth.