Stomata are the specialized pores or openings present in the epidermis of plant cells, which play a crucial role in gaseous exchange during the process of photosynthesis. Guard cells control the opening and closing of stomata.
- The turgor pressure, which is caused by the osmotic flow of water in the guard cells, controls the opening and closing of stomata.
- When the guard cells become turgid, they expand, causing stomata to open. Guard cells become flaccid as they lose water, causing stomatal closure.
- Stomata usually open when the leaf is exposed to light and close at night.