Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
A) is isotonic to the protozoan.
B) is hypotonic to the protozoan.
C) contains a higher concentration of solutes than the protozoan.
D) is hypertonic to the protozoan.

Question

Quizplus · Accepted Answer

Contractile vacuoles help protozoans to remove excess water from the cell in a hypotonic environment where there is a higher concentration of water outside the cell than inside. This process helps to maintain the osmotic balance of the cell. Therefore, the presence of contractile vacuoles suggests that the environment is hypotonic to the protozoan.

Some Protozoans Have Special Organelles Called Contractile Vacuoles That Continually