Here's why:
* Shape and Function: Guard cells are indeed shaped like sausages and occur in pairs surrounding a small opening called a stoma (plural: stomata).
* Gas Exchange: Stomata are the pores on the surface of a leaf that allow for the exchange of gases, specifically carbon dioxide (CO2) for photosynthesis and oxygen (O2) as a byproduct.
* Regulation: Guard cells control the size of the stomata opening. When they are filled with water, they become turgid (swollen) and open the stoma wider. When they lose water, they become flaccid (limp) and close the stoma.
Let me know if you have any other questions about plant cells or photosynthesis!
