If red blood cells are placed in a hypertonic solution, what will most likely happen to the cells?

• A. There will be no net movement of water because the solution is isotonic.
• B. They will lose water by osmosis and shrink (crenate).
• C. Water will move into and out of the cells at equal rates, causing the cells to remain the same size.
• D. They will gain water by osmosis and swell until they may lyse (hemolyze).

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the concept of tonicity, which describes the relative concentration of solutes outside the cell compared to inside the cell. A hypertonic solution has a higher solute concentration than the inside of the cell.
2. Step 2: Recall that water moves across the cell membrane by osmosis, moving from an area of lower solute concentration (inside the cell) to an area of higher solute concentration (outside the cell) to balance solute levels.
3. Step 3: Since the solution is hypertonic, water will move out of the red blood cells into the surrounding solution to try to equalize solute concentrations.
4. Step 4: As water leaves the cells, the red blood cells will lose volume and shrink, a process known as crenation.
5. Step 5: Therefore, the most likely outcome is that red blood cells placed in a hypertonic solution will lose water by osmosis and shrink (crenate).