Question

Which is the main function of RBC?
A. To fight diseases in the body
B. To carry oxygen to different parts of the body
C. To increase levels of WBC
D. To arrest bleeding

Answer 1

Hint: RBC is the red blood cells that consist of haemoglobin bound to it. It is the reason for its red colour and is the major component of the blood. It has a lifespan of about 120 days.

Complete answer: Red blood cells are also known as erythrocytes. It is formed in the red bone marrow and has a biconcave shape. The cytoplasm of red blood cells is enriched with haemoglobin which contains iron that binds to oxygen and carries throughout the body. The RBCs take in oxygen in the alveoli of the lungs via diffusion and in the process, it gives off carbon dioxide, which gets released as the byproduct of respiration. The systemic circulation of the blood plays an important role in the transport of gases to different parts of the body. The RBCs do not possess a nucleus and most organelles, in order to accommodate maximum space for haemoglobin; they can be viewed as sacks of haemoglobin, with a plasma membrane. Approximately 2.4 million new erythrocytes are produced every second in human adults. Each circulation takes about 60 seconds (one minute). Approximately 84% of the cells in the human body are 20–30 trillion red blood cells. Red blood cells carry nearly half of the blood’s volume (40% to 45%).
Hence, the correct answer is option B.

Note: RBC's carry oxygen bound with haemoglobin throughout the body for every muscle nourishment, contraction and relaxation in a manner to reduce hypoxic condition which will lead to cramping and lactic acid accumulation in muscles.