Question

When a freshwater protozoan is placed in marine water, the

• A. Contractile vacuoles disappear.
• B. Contractile vacuoles remain unchanged.
• C. Contractile vacuoles become bigger in size.
• D. Number of contractile vacuoles increases.

Answer 1

The correct option is A Contractile vacuoles disappear.

Water would pass from the cell to the surroundings, making it shrink and disappear by the process of osmosis. The function of vacuole is to expel out excess water.