AP BIOLOGY

Detailed explanation-1: -When guard cells gain water, they become turgid. In turgid guard cells the thin outer wall is pushed outside, which pulls the thick inner wall outside. This causes opening of stomata. When guard cells lose water, they become flaccid and inner wall of guard cells moves back towards the stomatal pore and pore closes.

Detailed explanation-2: -When guard cells are turgid, stomata open and when they are flaccid, stomata close. The opening and closing of stomata regulate the rate of transpiration. The stomata open during the day and close during the night. Stomata permit the plant to give out oxygen and take carbon dioxide for photosynthesis.

Detailed explanation-3: -Stomata are pores on the leaf surface, which are formed by a pair of curved, tubular guard cells; an increase in turgor pressure deforms the guard cells, resulting in the opening of the stomata.

Detailed explanation-4: -The increase in turgidity of guard cells opens the stomatal pore. Movement of potassium ions out from guard cells results in an increase in water potential, they lose water due to exosmosis, become flaccid and stomatal pore closes.

Detailed explanation-5: -Opening and closing of stomata take place due to turgor pressure that changes in guard cells. As the solute particles enter the guard cells from the epidermal and mesophyll cells, both the osmotic potential and the water potential of the guard cells get lowered.