What is the primary function of red blood cells (erythrocytes) in the human body?

• A. Initiate blood clotting by forming platelet plugs at sites of vascular injury
• B. Provide adaptive immune defense by producing antibodies against pathogens
• C. Transport oxygen and help carry carbon dioxide between the lungs and body tissues
• D. Filter pathogens and remove aged blood cells from circulation

Answer: (C)

Verified step by step guidance

1. Identify the main components and functions of red blood cells (erythrocytes) in the human body.
2. Recall that red blood cells contain hemoglobin, a protein responsible for binding oxygen molecules.
3. Understand that red blood cells transport oxygen from the lungs to body tissues and assist in carrying carbon dioxide from tissues back to the lungs for exhalation.
4. Differentiate the functions of other blood components: platelets are involved in blood clotting, white blood cells provide immune defense, and the spleen filters pathogens and aged blood cells.
5. Conclude that the primary function of red blood cells is to transport oxygen and help carry carbon dioxide between the lungs and body tissues.