Question

Stomata of desert plants remain closed during the daytime how do they take out co2 and perform photosynthesis

Answer 1

in CAM pathway in few desert plants the stomata closed in day to minimise water loss . The stomata are open at night and intake of CO₂
The CO₂ is stored as  malate acid  in vacuoles at night, and then in the daytime, the malate is transported to chloroplasts where it is converted back to CO₂ . This CO₂ used in photosynthesis .

Answer 2

Desert plants take up Carbon dioxide at night and prepare an intermediate which is acted upon by the energy absorbed by the chlorophyll during the day.