AP BIOLOGY

Detailed explanation-1: -Stomata are surrounded by two specialized cells called guard cells (Figure 17.1. 2.2. 1). Stomata must open to allow the gas exchange of carbon dioxide and oxygen for efficient photosynthesis (see Photorespiration), and light thus typically triggers stomatal opening.

Detailed explanation-2: -Upon the incoming of water inside the guard cells, they swell up to become like a curved banana surface, due to which the stomatal pore opens up. When the guard cells lose water, they become flaccid and straight and thus, close the stomatal aperture. Guard cells and stomata regulates the respiration process in plants.

Detailed explanation-3: -Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation. Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.

Detailed explanation-4: -Most plants regulate the size of stomata with guard cells. Each stoma is surrounded by a pair of sausage-shaped guard cells. In bright light the guard cells take in water by osmosis and become plump and turgid . In low light the guard cells lose water and become flaccid, causing the stomata to close.

Detailed explanation-5: -Guard cell function Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata. Light is the main trigger for the opening or closing. Each guard cell has a relatively thick cuticle on the pore-side and a thin one opposite it.