Which type of blood cells are primarily responsible for transporting oxygen and carbon dioxide?

Red blood cells, also known as erythrocytes, are primarily responsible for the transport of oxygen and carbon dioxide in the bloodstream. They contain a protein called hemoglobin, which binds to oxygen in the lungs and carries it to the tissues throughout the body. Once the oxygen is delivered, red blood cells pick up carbon dioxide, a waste product of cellular respiration, and transport it back to the lungs, where it can be exhaled.

This function of red blood cells is critical for maintaining the body's oxygen levels and facilitating the removal of carbon dioxide, thus playing a key role in respiratory and metabolic processes. Other blood components such as white blood cells, which are involved in immune defense, and platelets, which assist in blood clotting, do not have this primary role in gas transport. Plasma cells, a type of white blood cell, are primarily involved in antibody production and also do not transport oxygen or carbon dioxide.