What happens when a red blood cell loses its nucleus?

When a red blood cell (RBC) loses its nucleus, it becomes a mature erythrocyte, which allows it to maximize its capacity to carry oxygen. The absence of a nucleus creates more space for hemoglobin, the protein responsible for oxygen transport. This adaptation enhances the RBC's flexibility and ability to navigate through narrow capillaries. The loss of the nucleus also means that mature RBCs cannot divide or repair themselves, leading to a finite lifespan of about 120 days.