Structure- RBC or Red Blood Cell is the most abundant blood cell and is responsible for giving red color to blood. RBCs are scientifically termed as erythrocyte. Erythrocytes are produced from red bone marrow under the influence of erythropoietin through the process of erythropoiesis. They have a biconcave shape and diameter of a disc approx. 6 to 8 µm. The thickest portion that is the edge is around 2 to 3 µm and the thickness at the centre is around 1 µm. This disc like shape allows the RBC to pass through tiny vessels. The cytoplasm of RBC contains iron-protein biomolecular structure called hemoglobin. Human RBCs lacks nucleus to accommodate more volume of hemoglobin in each RBC. Heme is the iron part and globin are the protein part. This enables blood to carry oxygen (Bain,2017). Microscopic structure-