What is the name for red blood cells?

• A. leukocytes
• B. plasma
• C. thrombocytes
• D. erythrocytes

Answer: (D)

Red blood cells are named erythrocytes. This term comes from Greek roots meaning “red” and “cell,” reflecting their color and nature. Their main job is to transport oxygen from the lungs to tissues throughout the body, using the iron-containing protein hemoglobin that binds oxygen. Hemoglobin also helps carry some carbon dioxide back to the lungs for removal. The biconcave shape of these cells increases surface area for gas exchange and helps them flow through tiny vessels. In mammals, mature red blood cells lack a nucleus to maximize space for hemoglobin. They’re produced in the bone marrow and live about 120 days. Leukocytes are white blood cells involved in immunity; plasma is the liquid portion of blood; thrombocytes are platelets that help with clotting.