Like insects, plants must meet the opposing demands of water retention and gas exchange. The site of photosynthesis in plants, as well as the gas exchange site, is the leaf. This is what a section through a leaf looks like:
1. The mesophyll cells are surrounded by quite a lot of empty space for air to mingle around, providing plenty of surface area for gas exchange by diffusion.
2. Air with its carbon dioxide (necessary for photosynthesis) enters the leaf through the stomata. Stomata are holes on the leaf surface, made by the guard cells. They can open and close depending on environmental factors such as humidity, temperature and wind. This controls the amount of water loss. Oxygen, the byproduct of photosynthesis, also leaves the leaf through the stomata.
In addition to the stomata, there are special areas on the woody tissue of flowering plants that aids in gas exchange, called lenticels.
They look so familiar don’t they! I never knew until now that they do gas exchange. The lenticels are slightly different areas of the tissue with more pores.
Thank you for making all the content btw!
Serena Kutty YouTube
You explain everything so simply!
SecretDuck The Student Room
OFF TOPIC : I just want to say that your website is brilliant, thank you!!
I got A* in A-level biology (Cambridge), thanks! I love your videos
Sherif Negm Facebook
Just a huge thank you for spending your time helping others. I love your site and I'm seriously very grateful. No word of a lie
Neuron13 The Student Room