Question

why do desert plant take carbon dioxide and perform photosynthesis

Answer 1

The desert plants are adapted in such ways, that there is minimum loss of water.

Here also, the desert plants unlike other plants, upon up their stomata during the night and take up carbon dioxide.

This is not used up as photosynthesis can't be performed during night.

So the next day that carbon dioxide is used for photosynthesis in presence of sunlight.

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.