The guard cells are on either side of the stomata and control water loss and gas exchange by swelling to open the stomata and shrinking to close it. When open, gas exchange and water loss will occur. When closed, gas exchange and water loss does not occur.
Absorption is a process that takes place in the small intestines or ileum of the GI tract, in which simple and soluble nutrients are absorbed into the blood stream.
Absorption is enhanced by several adaptations of the gut such as large surface area of the gut which directly facilitates absorption of nutrients.
Presence of villi and microvilli in the gut increases the surface area for absorption of nutrients in the ileum.
