Which term describes a solution with a lower solute concentration than inside the cell?

• A. Hypertonic solution
• B. Isotonic solution
• C. Hypotonic solution
• D. Osmotic solution

Answer: (C)

Understanding tonicity means comparing solute concentrations inside the cell with those outside. When the outside solution has a lower solute concentration than inside the cell, water moves into the cell to balance the concentrations. This environment is called a hypotonic solution. In a hypotonic solution, the cell tends to swell as water flows inward. Hypertonic solutions have higher solute outside, causing water to leave and the cell to shrink; isotonic solutions have equal concentrations, so there’s no net movement of water. Osmotic describes the movement of water in response to solute differences and isn’t the specific label for this outside condition.