Hypotonic solution is a solution which has higher water potential than another solution.
Isotonic solution is a solution which has equal water potential as another solution.
Hypertonic solution is a solution which has lower water potential than another solution.
Effects of osmosis on animal cells
In hypotonic solution, more water molecules entering the cells than leaving the cells. The cells swell and burst (lysed).
In isotonic solution, water molecules entering and leaving the cells at equal amount. The size and shape of cells remain the same.
In hypertonic solution, more water molecules leaving the cells than entering the cells. The cells shrink (crenated).
Effects of osmosis on plant cells
In hypotonic solution, more water molecules entering the cells than leaving the cells. The cells swell and become turgid as the cell walls prevent the cells from bursting.
In isotonic solution, water molecules entering and leaving the cells at equal amount. The size and shape of cells remain the same.
In hypertonic solution, more water molecules leaving the cells than entering the cells. The cytoplasm shrinks away from cell walls (plasmolysed) and the cells become flaccid.