How do red blood cells survive without a nucleus?
Red blood cells are designed to pick up oxygen from the lungs and release it into the tissues of the body. This is their major function. The only reason that they can pick up and carry oxygen around is because they contain a protein within them called hemoglobin. If red blood cells (RBCs, or erythrocytes) have to carry oxygen, yet it is the hemoglobin inside them that carries the oxygen, you might expect that RBCs should be loaded with hemoglobin. In fact, they are! They load themselves up so much with hemoglobin to carry oxygen that their nuclei get in the way. So, RBCs don’t have any nuclei! 1/3 of their entire volume is due to hemoglobin! Regards.
