Oxygen in human body is transported by:

Question

Oxygen in human body is transported by:

1. A. blood (Correct answer)
2. B. lungs
3. C. nerves
4. D. muscles

Correct Answer

Option A — blood

Detailed Solution & Explanation

The correct answer is blood.

Key Points

• Oxygen is carried by the blood, bound to haemoglobin in the red blood cells as oxyhaemoglobin.
• The lungs are where gas exchange happens, but they do not transport oxygen around the body; nerves carry impulses and muscles produce movement.

Additional Information

• Each red blood cell holds about 270 million haemoglobin molecules, and each haemoglobin molecule can bind four oxygen molecules.
• Haemoglobin contains iron, which is why iron deficiency causes anaemia and reduced oxygen-carrying capacity.
• Most carbon dioxide travels back to the lungs dissolved as bicarbonate in the plasma rather than bound to haemoglobin.