What is the gas that the stomata take in and what are the substances that are expelled from these structures?
Carbon dioxide is taken in, oxygen is released out.
Stomata's primary function is gas exchange for the process of photosynthesis. The photosynthesis equation is:
Stomata open to take in carbon dioxide, and during that process, oxygen gas is released out as waste. When the weather is sunny and hot, the stomata are more likely to open to let carbon dioxide in for more photosynthesis, while oxygen will also escape.