How long does the average red blood cell typically live?

The average lifespan of a red blood cell is approximately 120 days. This duration is important for maintaining the proper balance and functionality of the blood. During their lifespan, red blood cells transport oxygen from the lungs to various tissues in the body and return carbon dioxide from the tissues back to the lungs. After about 120 days, they become less efficient at performing these vital functions and are typically removed from circulation by the spleen and liver.

Understanding the 120-day lifespan is crucial, as it informs various medical and veterinary practices, including blood cell turnover, anemia evaluation, and understanding the body's ability to regenerate red blood cells through the bone marrow in response to increased demands.

The other options either underestimate or overestimate this lifespan, which does not align with established scientific understanding of red blood cell physiology.