What structural feature of a leaf allows CO2 from the air to enter the leaf?
stomata
http://evolution.berkeley.edu/evolibrary/images/interviews/stoma_diagram.gif
The structural feature of a leaf that allows CO2 from the air to enter is called stomata. Stomata are tiny pores that are present on the surface of leaves. They can also be found on the surface of other plant organs such as stems and flowers. Each stoma is composed of two specialized cells known as guard cells that surround a small pore or opening.
To access this information and visualize the structure of stomata, you can refer to the provided link. The image shows a diagram of stomata with labeled parts. The pore in the center of the stomata allows gases like carbon dioxide (CO2) to move in and out of the leaf.
Stomata play a crucial role in gas exchange for plants. They regulate the passage of CO2, oxygen (O2), and water vapor (H2O) between the leaf and the surrounding environment. When plants need carbon dioxide for photosynthesis, the guard cells open the stomata to allow CO2 to diffuse into the leaf. This diffusion is driven by the concentration gradient of CO2 between the air outside and the air inside the leaf.