In the AQA textbook, it says that many air spaces in leaves allow carbon dioxide to come in contact with many cells so it has more efficient diffusion for carbon dioxide.
In the AQA textbook, it says that many air spaces in leaves allow carbon dioxide to come in contact with many cells so it has more efficient diffusion for carbon dioxide.
A larger surface area allows for more gas exchange. Think of the lungs: its a similar concept and one you'll come across a lot, especially in A level biology.