AP BIOLOGY

Detailed explanation-1: -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-2: -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. Stomata are tiny, microscopic and critical for photosynthesis.

Detailed explanation-3: -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-4: -The exchange of oxygen and carbon dioxide in the leaf (as well as the loss of water vapor in transpiration) occurs through pores called stomata (singular = stoma). Normally stomata open when the light strikes the leaf in the morning and close during the night.

Detailed explanation-5: -The only way for gases to diffuse in and out of the leaf is though small openings on the underside of the leaf, the stomata. These stomata can open and close according to the plant’s needs. The tissues of the leaf in between the epidermal cells, into which gases diffuse from the stomata, are called mesophyll.