How does the structure of the red blood cell allow it to carry out its functions?

The main function of the red blood cell is transport oxygen around the body to other cells. It contains haemaglobin which allows the binding of oxygen. Its biconcave shape maximises the surface area to increase efficiency of oxygen absorption. Its shape also allows it to ''squeeze'' through narrow vessels and can enter even the thinnest capillaries around the body. Red blood cells do not have a nucleus, which again increase the oxygen capacity.