Question

Question 28
Succulents are known to keep their stomata closed during the day to check transpiration. How do they meet their photosynthetic $C{O}_2$ requirements?

Answer 1

Succulent plants grow in dry and xeric conditions that's why they have to shut down the stomata during day time, to prevent water loss through transpiration. So the gaseous exchange does not take place.
These plants have devised a special method to ensure the supply of carbon dioxide during daytime. These plants fix carbon dioxide in the form of malic acid during night.