<P> Osmosis can be demonstrated when potato slices are added to a high salt solution . The water from inside the potato moves out to the solution, causing the potato to shrink and to lose its' turgor pressure' . The more concentrated the salt solution, the bigger the difference in size and weight of the potato slice . </P> <P> In unusual environments, osmosis can be very harmful to organisms . For example, freshwater and saltwater aquarium fish placed in water of a different salinity than that to which they are adapted to will die quickly, and in the case of saltwater fish, dramatically . Another example of a harmful osmotic effect is the use of table salt to kill leeches and slugs . </P> <P> Suppose an animal or a plant cell is placed in a solution of sugar or salt in water . </P> <Ol> <Li> If the medium is hypotonic relative to the cell cytoplasm--the cell will gain water through osmosis . </Li> <Li> If the medium is isotonic--there will be no net movement of water across the cell membrane . </Li> <Li> If the medium is hypertonic relative to the cell cytoplasm--the cell will lose water by osmosis . </Li> </Ol>

Discuss the conditions needed to cause water to diffuse into a cell