In a hypotonic solution, what happens to water movement?

• A. Water moves into the cell
• B. Water moves out of the cell
• C. The cell remains unchanged
• D. Water moves toward equilibrium without entering

Answer: (A)

Water moves into the cell in a hypotonic solution. Osmosis drives water across a semipermeable membrane from where water concentration is higher (fewer solutes outside) to where it is lower (more solutes inside). Because the outside has fewer solutes than the inside, water enters to balance the solute concentrations, causing the cell to swell. In animal cells this can lead to bursting if unchecked, while plant cells become turgid due to the cell wall resisting further expansion. The other scenarios describe incorrect directions or conditions for this situation.