Those organisms that have contractile vacuoles need them to expel incoming water due to osmosis. Otherwise the cell membrane will lysis from the pressure. read more
The contractile vacuole removes the excess water that enters the organism through osmosis (passive transport doest not require ATP) down a concentration gradient. Because the water is more concentrated on the outside of the organism in the fresh water of its habitat the water enters the organism by osmosis. read more
Contractile vacuoles are organelles that are involved in osmoregulation. It means that it balances the water and ionic level in the organism. For example, if the water level is too high in the organism , then the vacuole will collect the excess amount of water inside the body and release it out of the body. read more
Video: Contractile Vacuole: Definition & Function Contractile vacuoles are membrane-bound organelles that exist mainly in the cells of the kingdom Protista. In this lesson, we will examine their role and see some examples of organisms that have contractile vacuoles. read more
The contractile vacuole acts as part of a protective mechanism that prevents the cell from absorbing too much water and possibly lysing (rupturing) through excessive internal pressure. The contractile vacuole, as its name suggests, expels water out of the cell by contracting. read more