Question

Assertion : Transpiration occurs only when stomata are open.
Reason : Transpiration occurs only through stomata.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

Transpiration occurs through stomata, cuticles and lenticels. Stomata usually open during the day time and close during night. In 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.