human blood cells

Red blood cells carry a protein called hemoglobin which has a molecular structure adapted to transport oxygen to body tissues. This scanning electron micrograph shows the cells' characteristic donut-like shapes. • SIZE: The typical diameter of a human red blood...

Red blood cells carry a protein called hemoglobin which has a molecular structure adapted to transport oxygen to body tissues. The cells' flexibility allows them to flow through tiny capillaries. • SIZE: The typical diameter of a human red blood...