Explanation:
Red blood cells, also known as erythrocytes, are responsible for transporting oxygen throughout the human body. These cells contain a protein called hemoglobin, which has the ability to bind with oxygen molecules. When blood passes through the lungs, hemoglobin combines with oxygen to form oxyhemoglobin. This oxygen‑rich blood is then transported to different tissues and organs where oxygen is released for cellular respiration. Cellular respiration is the process through which cells produce energy needed for various body functions. Red blood cells have a unique biconcave disc shape which increases their surface area and allows efficient oxygen transport. Another special feature of mature red blood cells is that they do not have a nucleus, providing more space for hemoglobin. These cells are produced in the bone marrow and have an average lifespan of about 120 days. Old or damaged red blood cells are removed from circulation by the spleen and liver. If the number of red blood cells or the amount of hemoglobin decreases, a person may develop anemia, leading to fatigue and weakness. Because of their vital role in oxygen transport, questions related to RBC function are commonly asked in biology and general science examinations.