AP BIOLOGY

Detailed explanation-1: -If a cell is placed in an isotonic solution, there will be no net flow of water into or out of the cell, and the cell’s volume will remain stable. If the solute concentration outside the cell is the same as inside the cell, and the solutes cannot cross the membrane, then that solution is isotonic to the cell.

Detailed explanation-2: -When a red blood cell is placed in an isotonic solution, there will be no net movement of water. Both the concentration of solute and water are equal both intracellularly and extracellularly; therefore, there will be no net movement of water towards the solution or the cell.

Detailed explanation-3: -Isotonic means a solution with the same concentration as the cell. Hence water will move in and out of the cell at equal rates, so that the net movement of water is zero.

Detailed explanation-4: -So if a cell is kept in an isotonic solution, then the net movement of water across the cell will be zero. Hence, the water potential and the solute potential will be equal since, water potential is equal to solute potential at normal temperature and atmospheric pressure.

Detailed explanation-5: -In an isotonic solution, the flow of water in and out of the cell is happening at the same rate. Figure 8.4. 1: Red blood cells in hypertonic, isotonic, and hypotonic solutions.