Answer:
Diffusion
Explanation:
The diffusion is the transport of molecules. The molecules are transported from a region of higher concentration to lower concentration. The change in the volume of red blood cells occurs by the process of diffusion.
The RBCs carry oxygen and it is involved in transfer of oxygen from lungs. During the time of respiration in cell, a decline in level of oxygen and glucose occurs inside RBCs. The process of diffusion allows the movement of oxygen and glucose into RBCs.
