If a cell is placed in isotonic solution, what is the net movement of water?

If a cell is placed in isotonic solution, what is the net movement of water?

• A. Water moves into the cell
• B. No net movement
• C. Water moves out of the cell
• D. Both directions equally

Answer: (B)

In an isotonic solution, the solute concentration outside the cell is the same as inside the cell. Because the water potential on both sides is balanced, water still crosses the membrane, but the amount moving in equals the amount moving out. This equal exchange means there’s no overall change in the cell’s volume, so there is no net movement of water. Cells in isotonic environments therefore maintain their size and shape. So, the net movement of water is zero.

In an isotonic solution, the solute concentration outside the cell is the same as inside the cell. Because the water potential on both sides is balanced, water still crosses the membrane, but the amount moving in equals the amount moving out. This equal exchange means there’s no overall change in the cell’s volume, so there is no net movement of water. Cells in isotonic environments therefore maintain their size and shape.

So, the net movement of water is zero.