Human blood carries (more likely) oxygen than frog blood because (why?) It allows a person (what?)

Human blood carries more oxygen than frog blood. This is due to the different structure of red blood cells, which are responsible for the transfer of oxygen. In a frog, they are larger, erythrocyte cells are convex and have a nucleus. In humans, erythrocytes are small, have a biconcave shape and do not have a nucleus. Although in a frog red blood cells are larger in size, in a person their number is about 13 times more per unit volume of blood. This allows a person to lead a more mobile lifestyle and have a more complex body.