Explanation:
Osmoregulation. Paramecium and amoeba live in fresh water. Their cytoplasm contains a greater concentration of solutes than their surroundings and so they absorb water by osmosis. The excess water is collected into a contractile vacuole which swells and finally expels water through an opening in the cell membrane.
: Excretion of water in Paramecium is carried out by the Contractile vacuoles