The exchange system in plants including xerophytic plants

All plant cells require oxygen and carbon dioxide to carry out normal functions e.g. aerobic respiration and photosynthesis. In a plant, the volume of oxygen or carbon dioxide required changes depending on the rate of photosynthesis and respiration. 

Structure of a plant leaf and gas exchange

- No living cell is far from external air meaning there is a short diffusion pathway

- Diffusion takes place in the air, which makes it faster than if it occured in water

The majority of gas exchange in plants takes place in the leaves which are adapted for this in the followin ways:

- They have many small pores, stomata, which lead to shorter diffusion pathways

- There are many interconnecting open spaces within the mesophyll which allow gases to easily come into contact with the mesophyll cells

- The mesophyll cells have a large surface area which helps increase the…