Question: how do unicellular organisms like amoeba give out excess water and waste?
Answer: In some unicellular eukaryotic organisms (e.g., amoeba), cellular wastes, such as ammonia and excess water, are excreted by exocytosis as the contractile vacuoles merge with the cell membrane, expelling wastes into the environment. ... After the canals fill with water, it is pumped into the vacuole.