A major reason why the red blood cells can survive in the blood is that the

The major reason why the red blood cells can survive in the blood is that the blood plasma and the red blood cells are isotonic. This means that the concentration of solutes, such as salts and proteins, is the same in both the blood plasma and the red blood cells. As a result, there is no net movement of water across the cell membrane of the red blood cells, and they do not shrink or swell. This isotonicity helps to maintain the shape and integrity of the red blood cells, allowing them to carry oxygen and carbon dioxide throughout the body.