Which blood component is primarily responsible for oxygen transport?

• A. Platelets
• B. Plasma
• C. Hemoglobin
• D. White blood cells

Answer: (C)

Hemoglobin is the primary component of red blood cells responsible for the transport of oxygen in the bloodstream. This protein binds to oxygen in the lungs, where the concentration of oxygen is high, and releases it in tissues where the concentration is lower. The ability of hemoglobin to undergo conformational changes facilitates efficient oxygen uptake and delivery across different areas of the body.

Platelets are involved in blood clotting and do not play a role in oxygen transport. Plasma is the liquid component of blood that carries water, electrolytes, nutrients, and waste products but does not contain the specialized mechanisms required for oxygen transport. White blood cells are primarily involved in the immune response and defense against infections, again not contributing to the transport of oxygen. Thus, hemoglobin is uniquely essential for this vital function within the circulatory system.