Final answer:
Plasmolysis occurs because water exits the cell when the cell is in a hypertonic solution.
Step-by-step explanation:
Plasmolysis occurs because water exits the cell when the cell is in a hypertonic solution. In a hypertonic solution, the concentration of solutes outside the cell is higher than inside the cell, causing water to move out of the cell through osmosis. This results in the cell shrinking and the cell membrane detaching from the cell wall, a process known as plasmolysis.