AP BIOLOGY

Detailed explanation-1: -Stomata allow for gas exchange to occur, mainly carbon dioxide to enter the plant to make food molecules such as glucose and for oxygen to be released by the plant. It also allows water vapor to escape the plant via transpiration which is a necessary evil. Plants need to open and close the stomata.

Detailed explanation-2: -Through photosynthesis, they use sunlight and carbon dioxide to make food, belching out the oxygen that we breathe as a byproduct. This evolutionary innovation is so central to plant identity that nearly all land plants use the same pores-called stomata-to take in carbon dioxide and release oxygen.

Detailed explanation-3: -Carbon dioxide and oxygen cannot pass through the cuticle, but move in and out of leaves through openings called stomata (stoma = “hole"). Guard cells control the opening and closing of stomata. When stomata are open to allow gases to cross the leaf surface, the plant loses water vapor to the atmosphere.

Detailed explanation-4: -The three major substances that can pass through a plant’s stomata are water, oxygen, and carbon dioxide. Guard cells help regulate the plant’s water loss and can control how much of these substances are able to enter and exit by opening and closing the pore.

Detailed explanation-5: -Because plants must exchange gases through their stomata, closing them prevents plants from taking up carbon dioxide (CO2). Without CO2, plants cannot make carbohydrates, and plants can only obtain this critical molecule when stomata are open.