What would happen to a freshwater protozoan if removed from its normal habitat and placed into a saltwater pool?
a) loss of water through osmosis.
b) gain of water through osmosis.
c) loss of water through active transport.
d) gain of water through active transport.

The right answer is A) Loss of water through osmosis.

In biology, a hypertonic cellular environment (such as salt water) is an environment with a higher solute concentration than the cytoplasmic one. In a hypertonic environment, osmotic pressure causes water to leave the cell (this is called osmosis); the cytoplasm can become so concentrated that the cell has difficulty functioning.

In plant cells the effect is more dramatic. The cell membrane is detached from the cell wall, but the cells remain joined to their neighbors by points called plasmodesmes. Thus the cell takes the appearance of a pincushion, with the plasmodesmes ceasing to work for lack of space.