When a cell is placed in a hypertonic solution, the concentration of solutes outside the cell is higher than that inside the cell. To balance this concentration difference, water moves out of the cell through osmosis, causing the cell to lose water and shrink. This shrinkage can be observed under a microscope as the cell membrane pulls away from the cell wall in plant cells, a process known as plasmolysis.
On the other hand, when a cell is placed in a hypotonic solution, the concentration of solutes outside the cell is lower than that inside the cell. In this situation, water flows into the cell to balance the solute concentrations. As water enters, the cell swells and may even burst if too much water enters. In plant cells, this swelling generates turgor pressure against the cell wall, helping to maintain the plant’s structure.