Kaplan Nursing Entrance Exam Practice 2026 – Comprehensive Prep

Human red blood cells, or erythrocytes, are unique in their structure and function. One of the defining characteristics of mature human red blood cells is that they lack a nucleus. This anucleate state allows more space within the cell for hemoglobin, the protein responsible for oxygen transport. By not having a nucleus, red blood cells can carry a greater amount of hemoglobin, which is crucial for their primary role in delivering oxygen throughout the body and facilitating the removal of carbon dioxide.

In terms of production, while red blood cells are ultimately formed in the bone marrow, the spleen plays a role in filtering and recycling old or damaged red blood cells but is not the primary site of production. Furthermore, mature red blood cells do not have the capability to reproduce; they are produced via a process called erythropoiesis from precursor cells in the bone marrow.

Thus, the absence of a nucleus in mature human red blood cells is significant for their function and efficiency in transporting oxygen and carbon dioxide, making this feature a critical aspect of their biology.