Question

The stomatal closure in plants at night, takes place to prevent the loss of

• A. O${}_2$
• B. H${}_2$O
• C. CO${}_2$
• D. Energy
• E. Chlorophyll

Answer 1

The correct option is B H${}_2$O

The stomata are the pores in the plants which allow gas exchange and loss of water. At night, in the absence of light, there is no carbon dioxide fixation and so, carbon dioxide is not taken in through the stomata. If the stomata remains open, then there will be water loss. So, to minimise water loss at night, the stomatal pores gets closed.

Thus, the correct answer is option 'H${}_2$O'.