MCQ Detailed View

Red Blood Cells (RBCs), also known as erythrocytes, are one of the most vital components of human blood. Their primary function is to transport oxygen from the lungs to all parts of the body and to carry carbon dioxide back to the lungs for exhalation. The average lifespan of a red blood cell is approximately 120 days in a healthy adult human body.

RBCs are produced in the bone marrow through a process called erythropoiesis. They lack a nucleus and most organelles, which allows them to carry more hemoglobin, the protein responsible for binding oxygen. However, this also limits their ability to repair themselves, resulting in a fixed lifespan.

After about 120 days, old or damaged RBCs are removed from circulation primarily by the spleen and sometimes by the liver. Specialized cells called macrophages break down these old cells, recycling iron and some other components to form new RBCs. The continuous production and removal of RBCs ensure a healthy balance in blood oxygen-carrying capacity.

Other given options are incorrect:

• 
  

  60 days: Too short; even under certain conditions like anemia, the lifespan is rarely this short.

  
  


• 
  

  180 or 240 days: Too long; RBCs naturally deteriorate due to lack of repair mechanisms and usually cannot survive beyond 120 days.

  
  

Maintaining healthy red blood cells is crucial for overall well-being. Diseases like anemia, sickle cell disease, or hemolytic disorders can reduce their lifespan significantly, leading to low oxygen levels and fatigue. A proper diet rich in iron, vitamin B12, and folic acid supports healthy RBC production.

This question belongs to Biology, specifically the branch of human physiology and hematology, which studies blood cells and their life processes.