Question

Average life span of human RBC is
A.100 days
B.90 days
C.120 days
D. None of the above

Answer 1

Hint: RBCs are the red blood cells present in the blood which contains hemoglobin which helps in transfer of oxygen and carbon dioxide.

Complete answer:
We know that RBC is red blood cells. Lets know a little more about red blood cells before analyzing the options. Human blood has 4 constituents namely RBC,WBC, platelets and plasma. Plasma is made up of protein, water and salts. This forms the liquid part of the blood. The solid part is formed by red blood cells, white blood cells and platelets. RBC are round and flat with a dent on the centre. Hemoglobin is the protein present inside red blood cells. They carry oxygen into all the body parts and remove carbon dioxide from the body parts to the lungs for exhaling, Where white blood cells help in providing immunity to the body and platelets help in preventing bleeding. The life span of red blood cells vary from 70 days to 160 days. Its average life span is 120 days. They are destroyed in an organ called spleen.
Option A) Average lifespan of red blood cells is not 100 days. Therefore this is an incorrect option
Option B) Average lifespan of red blood cells is not 90 days. Therefore this is a incorrect option
Option C) Average lifespan of red blood cells is 120 days, Therefore this is the correct option
Option D) This option is not relevant. Therefore this is an incorrect option

Blood is fluid connective tissue which has 55% plasma and 45% formed elements like RBC, WBC and platelets. Blood plays a huge role in digestive processes. Nutrients like glucose, amino acids etc after digestion from the capillaries in villi that lines the small intestine are absorbed into the bloodstream. Blood also transports certain hormones to target tissues from endocrine glands. Blood also regulates body temperature through homeostasis. At the sites of injury, platelets form a clot using threads called fibrins to prevent bleeding. Toxins are removed into the kidney and liver from blood. These toxins include urea, uric acid, alcohol etc.

Hence, the correct answer is option (C).

Note: All red blood doesn’t live 120 days. It varies from 70 to 160. It can live only 100 or 90 days also. But the question has mentioned the average life span, which is 120 days