Question

Stomata of desert plants remain closed during day time. How do they take up carbon dioxide and perform photosynthesis?

Answer 1

In desert plants the stomata open at night.
They take in carbon dioxide at night, and is stored in the form of an intermediate which is used during day for photosynthesis (When the stomata are closed).
Also, chlorophyll of the plant are located in the stem as levesare reduced to spines and stem takes the function of photosynthesis.

Such plants undergo CAM photosynthesis as they open up their stomata during night and take in CO2.Stomata remains close during the day time to prevent the loss of water by transpiration. They store the CO2 in their cells until the sun comes out and they can carry on with photosynthesis during the day time.