Question

Assertion: Transpiration occurs only when stomata are open.

Reason: Transpiration occurs only through stomata.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

The correct option is: (d)

Explanation:

Transpiration occurs through stomata, cuticles and lenticels. Stomata usually open during the day time and close during night. ln succulents or CAM plants, the stomata remain closed during the day and open only during the night. As cuticle, lenticel and bark lack any mechanism of closure, transpiration occurs throughout day and night.