AP BIOLOGY

Detailed explanation-1: -Water moves from the xylem into the mesophyll cells, evaporates from their surfaces and leaves the plant by diffusion through the stomata.

Detailed explanation-2: -Evaporation from the mesophyll cells produces a negative water potential gradient that causes water to move upwards from the roots through the xylem.

Detailed explanation-3: -Transpiration is the evaporation of water from plants occurring at the leaves while their stomata are open for the passage of CO2 and O2 during photosynthesis.

Detailed explanation-4: -When the plant opens its stomata to let in carbon dioxide, water on the surface of the cells of the spongy mesophyll and palisade mesophyll evaporates and diffuses out of the leaf. This process is called transpiration . Water is drawn from the cells in the xylem to replace that which has been lost from the leaves.

Detailed explanation-5: -The process of photosynthesis occurs in a middle layer called the mesophyll. The gas exchange of carbon dioxide and oxygen occurs through small, regulated openings called stomata (singular: stoma ), which also play a role in the plant’s regulation of water balance.