What component of blood is primarily responsible for oxygen transport?

Red blood cells, also known as erythrocytes, are primarily responsible for the transport of oxygen in the blood. They contain a protein called hemoglobin, which has a strong affinity for oxygen. When red blood cells circulate through the lungs, hemoglobin binds to oxygen molecules, allowing for efficient transport through the bloodstream to various tissues and organs in the body. This oxygen delivery is crucial for cellular respiration, where cells utilize oxygen to produce energy.

In contrast, plasma serves as the liquid component of blood that carries nutrients, hormones, and waste products but does not participate directly in oxygen transport. White blood cells are part of the immune system and play a role in defending the body against infection, while platelets are involved in blood clotting mechanisms. Thus, while all these components are essential for various functions of the blood, it is the red blood cells that are specifically tasked with the critical job of oxygen transportation.