Final answer:
The contractile vacuole is a type of vacuole found in protists that removes excess water from the cell. It uses exocytosis to expel the water into the environment.
Step-by-step explanation:
The contractile vacuole is a type of vacuole found in protists, such as the paramecium. Its main function is to remove excess water from the cell and prevent it from bursting in a hypotonic environment. The process by which the contractile vacuole excretes excess water is called exocytosis, where the vacuole merges with the cell membrane and expels the water into the environment. The contractile vacuole is a type of vacuole found in protists that removes excess water from the cell. It uses exocytosis to expel the water into the environment.