Which component of blood is primarily responsible for carrying oxygen?

Red blood cells are primarily responsible for carrying oxygen in the blood. They contain hemoglobin, a specialized protein that binds to oxygen in the lungs and transports it to tissues throughout the body. The structure of red blood cells, which are biconcave discs, increases their surface area for gas exchange and allows for efficient oxygen transport. Each red blood cell can carry approximately four molecules of oxygen, maximizing the amount of oxygen delivered to various tissues.

In contrast, platelets are primarily involved in the clotting process, helping to prevent bleeding. White blood cells play a crucial role in the immune system, defending the body against infections and foreign invaders. Plasma, the liquid component of blood, serves as a transport medium for nutrients, hormones, and waste products, but it does not carry oxygen directly. Therefore, while all these components are vital for different functions within the body, it is red blood cells that have the primary role in oxygen transport.