Red blood cells, also referred to as erythrocytes, are responsible for transporting what in the blood?

Red blood cells, or erythrocytes, play a crucial role in the circulatory system by transporting gases in the blood, primarily oxygen and carbon dioxide. These cells contain hemoglobin, a protein that binds to oxygen in the lungs and carries it to tissues throughout the body. Once the oxygen is delivered to the tissues, hemoglobin binds to carbon dioxide (a waste product of metabolism) in those tissues and transports it back to the lungs for exhalation.

This dual function of transporting both oxygen and carbon dioxide is what makes red blood cells vital for maintaining the body's respiratory and metabolic processes. While nutrients and hormones, electrolytes, and water are important components of blood, they are primarily carried by plasma and other cellular components, not specifically by red blood cells. Therefore, the selection of the option that states red blood cells are responsible for transporting both oxygen and carbon dioxide accurately reflects their key physiological role in the body.