MICROANATOMY

Detailed explanation-1: -Human red blood cells (RBC), after differentiating from erythroblasts in the bone marrow, are released into the blood and survive in the circulation for approximately 115 days.

Detailed explanation-2: -Red blood cells have a limited lifespan because they don’t have a center membrane (nucleus). When a red blood cell travels through your blood vessels, it uses up its energy supply and only survives an average of 120 days.

Detailed explanation-3: -So, the correct answer is ‘120 days’

Detailed explanation-4: -The lifespan of RBC is about 120 days.