Frog RBCs contain a DNA-bearing nucleus that is visible in the center of the cell. Human RBCs do not possess nucleus along with other cell organelles such as mitochondria, Golgi apparatus and endoplasmic reticulum in order to accommodate greater amount of haemoglobin in the cells. Denucleation of rbcs is an adaptation, Which makes the mammalian red blood cell effective at transporting oxygen/eliminating CO2.
