A solution which has a lower osmotic concentration (high water potential) than another solution is said to be hypotonic. If two solutions are of equal concentration they are isotonic.
A plant cell behaves differently from an animal cell when placed in a hypotonic solution. Since the cell sap has a lower water potential than that of the solution outside the living cell, water enters the cell by osmosis (endosmosis). Note, that the partially permeable membrane here is the plasma membrane and not the cellulose cell wall. The cellulose cell wall is permeable and allows most dissolved substances to pass through.
As water enters the cell the vacuole increases in size and pushes the cell contents against the cellulose wall. The plant cell does not burst because the cell wall is strong and relatively inelastic. It prevents over expansion of the cell by exerting an opposing pressure preventing the entry of more water. When the cell is in this state, it becomes rigid or turgid. This rigidity of the cell with water is called turgor. The pressure exerted by the water on the cell wall is the turgor pressure.
On the other hand an animal cell will swell and may burst in a hypotonic solution.
A plant cell behaves differently from an animal cell when placed in a hypotonic solution. Since the cell sap has a lower water potential than that of the solution outside the living cell, water enters the cell by osmosis (endosmosis). Note, that the partially permeable membrane here is the plasma membrane and not the cellulose cell wall. The cellulose cell wall is permeable and allows most dissolved substances to pass through.
As water enters the cell the vacuole increases in size and pushes the cell contents against the cellulose wall. The plant cell does not burst because the cell wall is strong and relatively inelastic. It prevents over expansion of the cell by exerting an opposing pressure preventing the entry of more water. When the cell is in this state, it becomes rigid or turgid. This rigidity of the cell with water is called turgor. The pressure exerted by the water on the cell wall is the turgor pressure.
On the other hand an animal cell will swell and may burst in a hypotonic solution.