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contractile vacuole
contractile vacuole A membrane-surrounded cavity in a cell that periodically expands, filling with water, and then suddenly contracts, expelling its contents to the cell's exterior. It is thus an organ of osmoregulation and excretion. Contractile vacuoles are common in freshwater sponges and typical of freshwater protoctists, such as Amoeba (which has one spherical vacuole) and Paramecium (in which a number of accessory vacuoles are attached to a main vacuole).
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"contractile vacuole." A Dictionary of Biology. 2004. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "contractile vacuole." A Dictionary of Biology. 2004. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O6-contractilevacuole.html "contractile vacuole." A Dictionary of Biology. 2004. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-contractilevacuole.html |
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contractile vacuole
contractile vacuole In many freshwater, unicellular organisms, a membranebound cavity that expands and contracts with a pulsating movement as it takes in water from the cell contents and expels it from the cell. Contractile vacuoles serve to regulate the water content of the cell.
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MICHAEL ALLABY. "contractile vacuole." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "contractile vacuole." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O7-contractilevacuole.html MICHAEL ALLABY. "contractile vacuole." A Dictionary of Plant Sciences. 1998. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-contractilevacuole.html |
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contractile vacuole
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Cite this article
MICHAEL ALLABY. "contractile vacuole." A Dictionary of Zoology. 1999. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "contractile vacuole." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O8-contractilevacuole.html MICHAEL ALLABY. "contractile vacuole." A Dictionary of Zoology. 1999. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-contractilevacuole.html |
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