When a cell is placed in water, the water molecules move into the cell by osmosis. This process continues until the concentration of water inside and outside the cell is the same.

If the concentration of water outside the cell is higher than inside, water will move into the cell. This can cause the cell to swell and burst.

If the concentration of water outside the cell is lower than inside, water will move out of the cell. This can cause the cell to shrink and die.

The ability of a cell to maintain its proper water balance is essential for its survival.