Question

Water moves osmotically into Paramecium, a single celled protistan of aquatic habitats. If unchecked, the influx of water would bloat the cell and rupture its plasma membrane. An energy-requiring mechanism involving contractile vacuoles expels the excess water from inside. Water enters tube-like structures into this organelle, and collects in a central space in the vacuole. When full, the vacuole contracts and squirts the excess water out of a pore that opens to the outside. Are the fluids surrounding s hypotonic, hypertonic or isotonic relative to the Paramecium’s internal fluid (cytoplasm)? Explain your answer.

Answer 1

Ans- Paramecium lives in a hypotonic environment ( The fluid surrounding the paramecium is hypotonic to the cytoplasm of the paramecium) Thwt collect water flowing in and pump it out but to prevent them from over expanding through the two contractile vacuoles pump the water back outside (water constantly enters the cell which is then removed by the contractile vacuole).Water will always move from area of low solute concentration (high water concentration) to an area of high solute concentration (cytoplasm).