Answer:
Stomata - specialized cells that contract and expand to open or close pores for gas exchange. Stomata can adjust to temperature, staying closed when temperatures are hot and dry to prevent gas and water loss.
Explanation:
Stomata (singular stoma) are pores found in the epidermis of plant leaves. Stomata open and close in response to the change in structure of two guard cells either side of the pore opening. When the guard cells are turgid, the stomata open, when they are flaccid, they are closed.
This functions to permit gas exchange while preventing the loss of water, especially during hot, dry weather. The stomata can only open when the guard cells are turgid, pulling the stomata apart.