How many types of osmosis are there? and please explain hypotonic solution, hypertonic solution and isotonic solution with examples.
The two types of osmosis are:
i) Exosmosis
ii) Endosmosis
Exosmosis: Movement of water molecules out of a cell when the cell is placed in hypertonic solution.
Endosmosis: Movement of water molecules into the cell when the cell is placed in hypotonic solution.
If the medium/solution surrounding the cell has a higher water concentration than the cell, the solution is known as a hypotonic solution. Here the cell will gain water by osmosis. Example - distilled water
If the medium has exactly the same water concentration as the cell, the solution is known as an isotonic solution. There will be no net movement of water across the cell membrane and the cell will stay the same size. Example - Isotonic saline
If the medium has a lower concentration of water than the cell, meaning that it is a very concentrated solution, the solution is known as a hypertonic solution. The cell will lose water by osmosis. Example - Concentrated salt solution.