What type of blood cell is primarily involved in oxygen transport?

The erythrocyte, commonly known as a red blood cell, is primarily responsible for oxygen transport within the body. These cells contain a protein called hemoglobin, which binds to oxygen molecules in the lungs and carries them through the bloodstream to tissues and organs that require oxygen for metabolic processes. The structure of erythrocytes, which are biconcave discs, allows for a larger surface area for oxygen absorption and efficient gas exchange.

In contrast, leucocytes, or white blood cells, play a critical role in the immune response and fighting infections rather than transporting oxygen. Platelets are involved in blood clotting and also do not have a role in oxygen transport. Stem cells, while they are the precursors to various types of blood cells, including erythrocytes, are not directly involved in transporting oxygen themselves. Thus, the specialization of erythrocytes makes them uniquely suited for the vital task of oxygen transport in the body.