BiologyCode 9700
Homeostasis in plants
What this topic asks you to be able to do
- explain that stomata open and close in response to changing environmental conditions, and that regulating the stomatal aperture strikes a balance between taking up carbon dioxide by diffusion and keeping water loss by transpiration as low as possible
- explain that stomata open and close in a daily rhythm
- describe how guard cells are built and what they do, and explain the mechanism they use to open and close stomata
- describe the part abscisic acid plays in making stomata close when water is scarce (water stress), including how calcium ions act as a second messenger