Question

All students performed an experiment in which they put two different cells P and Q in pure water. Cell P swelled up and burst eventually while cell Q became tight and firm but did not burst.
Which of the following is the most appropriate inference?

• A. Cell sap of cell P is isotonic to the pure water.
• B. Cell sap of cell Q is isotonic to pure water.
• C. Cell P has been obtained from a plant.
• D. Cell Q is a bacterium.

Answer 1

The correct option is D Cell Q is a bacterium.

The bacterium contains cell wall around the cell membrane. It works as a protective layer against the external environment. This layer is rigid than the cell membrane. As the bacterium is put in the hypo-osmotic environment, water enters the cell via endosmosis and the cell swells up. The internal turgor increases due to this and it puts pressure on the bacterial wall but it does not burst as the cell wall is rigid and gives support.

Hence the correct option is D.