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Contractile vacuoles — function
publish date: 2026/06/16 20:56:49.967328 UTC
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Some single-celled organisms have a specialized type of vacuole that is important in expelling excess water and waste from the cell. What are these called?
Correct Answer
contractile vacuoles
Explanation
Contractile vacuoles are found in some single-celled organisms such as Paramecium and Amoeba. They rhythmically contract to expel excess water and waste from the cell, preventing it from swelling and bursting due to the constant influx of water by osmosis. This is especially important in freshwater organisms where the external medium is very dilute.
Reference
Biology: A Self-Teaching Guide