Plants absorb [[1]] from the atmosphere through little pores called [[2]] that are present on the surface of the leaves and are surrounded by [[3]]. 

Plants require carbon-dioxide gas for the process of photosynthesis. This carbon-dioxide is converted into sugar by this process.

There are pores present in the surface of leaves which help in transpiration and exchange of gases, they are known as stomata. As a result, plants use these openings to absorb carbon dioxide from the atmosphere (stomata).

The stomata present on the leaves consists of a central pore called stoma surrounded by two cells that are known as guard cells. When these cells are turgid the stomata opens and when these cells lose water and turn flaccid the stomata closes.