Final answer:
Water movement in or out of a cell's vacuole depends on the relative solute concentrations of the intracellular and extracellular environments. In a hypotonic solution, water moves into the vacuole while in a hypertonic solution, water exits the vacuole. No net movement occurs in an isotonic solution.
Step-by-step explanation:
Water movement into or out of a vacuole in a cell varies depending on the osmotic conditions of the surrounding environment relative to the inside of the cell. In a hypotonic solution, where the solute concentration is lower outside than inside the cell, there is a net influx of water into the cell, as water moves from an area of lower solute concentration to higher solute concentration via osmosis.
This may cause the cell to swell and eventually lyse if the cell wall does not counteract the osmotic pressure. Conversely, in a hypertonic solution, where there is a higher solute concentration outside the cell than inside, water will move out of the cell, potentially leading to plasmolysis where the cell membrane detaches from the cell wall. If the solution is isotonic, there will be no net movement of water since the solute concentrations are balanced inside and outside the cell.