Final answer:
The statement that a human red blood cell is normally 0.9% salt which hypotonic is false. Isotonic solutions, such as 0.9% NaCl, maintain cell volume, while hypotonic solutions cause cells to swell or burst.
Step-by-step explanation:
When you state that a human red blood cell is normally 0.9% salt which hypotonic, the statement is False. Cells are exposed to isotonic, hypotonic, and hypertonic solutions which have different effects on their volume.
A hypotonic solution has a lower concentration of solutes compared to the inside of a cell, which causes water to move into the cell, potentially causing it to swell or even burst in a process known as hemolysis. In contrast, isotonic solutions have the same concentration of solutes as inside the cell, thus maintaining cell volume and shape. Typical isotonic solutions include 0.9% NaCl or 5% glucose in water, which match the solute concentration of human blood serum. Therefore, red blood cells in an isotonic solution would not experience osmotic pressure that leads to swelling or bursting.