Answer:
The protein inside (a) red blood cells that carries oxygen to cells and carbon dioxide to the lungs is (b) hemoglobin. Hemoglobin is made up of four symmetrical subunits and four heme groups. Iron associated with the heme binds oxygen. It is the iron in hemoglobin that gives blood its red color.
Blood transport oxygen, mineral absorbed from food. RBC's are associated with oxygen transport it contains hemoglobin that is why it transport oxygen. Oxygen combine with hemoglobin and form oxyhemoglobin and transport oxygen.
