Question

Why are contractile vacuoles more active in freshwater?

Answer 1

Contractile vacuoles are more active in freshwater because:

1. Amoeba can be found in both freshwater and marine environments.
2. The contractile vacuole is required in freshwater amoebae because freshwater has a lower concentration of solutes than the amoeba's own internal fluids.
3. In freshwater amoeba, if the contractile vacuole is missing, the cell will fill up with water and finally rupture.
4. Marine amoeba usually lack a contractile vacuole because the concentration of solutes within the cell is in balance with the tonicity of the surrounding water. As a result, they do not require osmoregulation.