What type of blood cell is primarily responsible for transporting oxygen?

The primary function of red blood cells is to transport oxygen throughout the body. These cells contain hemoglobin, a protein that binds to oxygen molecules in the lungs and carries them to various tissues and organs. The structure of red blood cells, which includes their biconcave shape, maximizes their surface area for oxygen absorption and allows them to navigate through the narrowest capillaries. This unique adaptation is essential for efficient oxygen delivery, making red blood cells critical for maintaining proper cellular function and overall health.

In contrast, platelets are involved in blood clotting and do not play a role in oxygen transport. White blood cells are part of the immune system and help defend the body against infection but are not responsible for oxygen transport. Stem cells are unique cells with the potential to develop into various types of cells but do not have a direct role in oxygen transport. Thus, red blood cells are clearly identified as the key players in oxygen transportation.