Question

Contractile vacuole is generally absent in the
A) Parasitic protozoans
B) Marine protozoans
C) Both (a) and (b)
D) Some fresh water protozoans

Answer 1

the answer to the question is b

Answer 2

Contractile vacuoles are absent in both parasitic and marine pathogens. So the correct option is C.

Contractile vacuoles are a type of vacuoles that are present to drain the excess of water accumulated in the cells.

They are not present in the parasitic and marine protozoans because an isotonic condition occurs both inside and out of the cells in these organisms.

Whereas in a freshwater protozoan the salt content inside the cell is more than that of the external region and hence it requires osmoregulation.