HYPOTONIC SOLUTIONS : If the medium surrounding the cell has a higher water concentration than the cell meaning that the water solution is very dilute the cell will gain water by Osmosis such a solution is known as hypotonic solution . water molecules are free to pass across the cell membrane in both direction but more water will come into the cell then leave . the net( overall) result is that water enters the cell ...the cell is likely to swell up ..
ISOTONIC SOLUTION : is the medium has exactly the same water concentration as the cell there will be no movement of water across the cell membrane such a solution is known as isotonic solution. water crosses the cell membrane in both direction but the amount going in is the same as the amount going out so there is no overall moment of water the cell will stay the same size .
HYPERTONIC SOLUTION : is the medium has a lower concentration of water than the cell meaning that it is very concentrated solution the cell will lose water by Osmosis such a solution is known as hypertonic solution. again, water crosses the cell membrane in both direction but this time more water loses the cell then enter it therefore the cell will shrink .