There are 3 main types of cells in the blood.
* Red blood cells
* White blood cells
* Blood platelets.
Out of which, major portion is red blood cells and that is why blood appears red in color.
Red color in these cells comes due to presence of hemoglobin which is an Iron compound. Iron has the property of reflecting red light. When hemoglobin is carrying a lot of oxygen (like when just leaving the lungs), blood is bright red. When most of the oxygen has been released to the body, blood is dark red.
Tags:
Why