hypotonic solution means a solution with a higher water potential than the cell
isotonic is the solution with the same amount of water potential with the cell
in animal cell, it only has a semi permeable membrane, therefore when put in hypotonic solution, water molecules will move from the solution to inside the cell by osmosis. the cell may gain so much water that it may burst
in isotonic solution, the net movement of water molecules will be same in each direction , as the water potential is same. that way the cell will not gain or loss water and remain it oiriginals shape
however in plant cells, it has a cell wall. it prevents the cell from bursting. so when put in hypotonic, the cell gain water,but not burst, the cell membrane just push against the cell wall and the cell become turgid
in isotonic solution, same animal cell , no change
