Transpiration and stomata

• Guard cells are adapted to open and close stomata
• They have a kidney shape
• Lots of water guard cells fill with it and go plump this makes stomata open so gases can be exchanged for photosynthesis
• When short to water guard cell becomes flaccid making stomata close this helps stop water escaping
• Thin outer walls and thickened inner walls help make opening and closing work
• Sensitive to light and close at night to save water
• Underside of leaves so less water is lost