Final answer:
The statement that contractile vacuoles remove water from cells is true. These organelles are essential for unicellular organisms in hypotonic environments to prevent cell lysis, and they act by the process of exocytosis, expelling excess water and waste from the cell.
Step-by-step explanation:
Contractile vacuoles do indeed remove water from cells. This statement is true. Contractile vacuoles are specialized organelles in certain unicellular organisms living in hypotonic environments, like freshwater. The main function of these vacuoles is to excrete excess water and waste by the process of exocytosis. Organisms such as paramecia and amoebae rely on their contractile vacuoles to pump water out of the cell. This not only expels waste but also helps prevent the cell from lysing due to an overabundance of water entering the cell by osmosis.
For example, freshwater protists have contractile vacuoles surrounded by several canals that absorb water from the cytoplasm. Once these canals fill with water, it's pumped into the vacuole, and, when full, the vacuole expels the water through a pore.
Contractile vacuoles differ from other vacuoles that serve functions like storing food or water, or expelling chemicals to deter predators. It's important to note that while contractile vacuoles are more active in hypotonic situations where there's a lot of water to be expelled, they may become less efficient in solutions of high osmolarity due to reduced ATP production.