AP BIOLOGY

Detailed explanation-1: -Complete answer: The stomatal pore is surrounded by a pair of parenchyma cells known as guard cells that plays an important role in regulating the opening and closing of the stomata and in turn plays a role in the exchange of gases.

Detailed explanation-2: -Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata.

Detailed explanation-3: -Beneath the hypodermis, the palisade and spongy mesophylls are arranged as in a mesophytic leaf. There are more layers of hypodermis between the spongy mesophyll and the lower epidermis. There are invaginations in the lower epidermis called stomatal crypts. Stomata are located within these, surrounded by trichomes.

Detailed explanation-4: -Their function is to prevent water getting out and stopping unwanted substances/organisms getting in. The palisade mesophyll layer is where most of the photosynthesis occurs in the leaf. The palisade cells contain a lot of chloroplasts to help them perform this photosynthesis.

Detailed explanation-5: -Many plant leaves have two layers of photosynthetic tissue: the palisade and spongy mesophyll. Whereas palisade mesophyll consists of tightly packed columnar cells, the structure of spongy mesophyll is not well characterized and often treated as a random assemblage of irregularly shaped cells.