Discussion:
A description of rare and normal blood types.
Our blood is made up of plasma (water, nutrients, gases, wastes, hormones and proteins), white blood cells (leukocytes) for immunity, platlets (cell fragments to form blood clots when we are cut) and red blood cells (erythrocytes). Red blood cells make our blood red because they contain hemoglobin which exchange gases like oxygen and carbon dioxide between the tissue and the lungs. Hemoglobin contains iron which gives us the red colour. Your car rusts because it contains iron and rust is brown. It is the same reason your blood turns brown after it is dry because it too "rusts" or oxidizes. The reason for different blood types is due to antigens, ABO groups, and the Rh factor.