How are protozoan adapted to live in a hypotonic environment?

Answer 1

Living in a hypotonic environment means that more water enters the cell than leaves the cell. Protozoa would swell up with the excess water and possibly break open if they didn't have a way to get rid of the extra water. Protozoa have special organelles called "contractile vacuoles" to collect and expel the excess water. These are easily seen in paramecia and others.

Answer 2

contractile vacuoles eject excess water.
hypotonic is more pure water than hypertonic.