question_answer

People living at sea level have around 5 million RBC per cubic millimetre of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitudes

A)  Atmosphericlevel is less and hence more RBC's are needed to absorb the required amount of  to survive.

B)  There is more UV radiation which enhances the RBC production.

C)  People eat more nutritive food; therefore more RBC's are formed.

D)  People get pollution-free air to breathe and more oxygen is available.

Correct Answer: A

Solution :

At the altitude of 5400 meters the low atmospheric pressure of  will be too low so the solubility of oxygen in the blood will be very less hence, the oxygen carried by each RBC will be too less. But to fulfil the oxygen requirement of the body, the blood has to carry more oxygen to the body tissue and this is done by the increased number of RBC's. Hence, the correct option is [a].