Which one of the following human cells is devoid of a nucleus?

Mature human red blood cells (erythrocytes) are devoid of a nucleus. During the process of erythropoiesis in the bone marrow, these cells expel their nucleus and other organelles (like mitochondria) to maximize the space available for hemoglobin, the iron-containing protein responsible for oxygen transport. This structural adaptation also results in their characteristic biconcave shape, which increases the surface area for gas exchange and allows them to be flexible enough to navigate through narrow capillaries.

• Nerve cells (neurons), bone cells (osteocytes), and white blood cells (leukocytes) are all nucleated cells that require a nucleus to manage cellular functions, protein synthesis, and genetic regulation.