Organisms and Populations Question 60
60. People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitude
[1995, 2006]
(a) atmospheric $O_2$ level is less and hence more $RBCs$ are needed to absorb the required amount of $O_2$ to survive
(b) there is more UV radiation which enhances RBC production
(c) people eat more nutritive food, therefore more RBCs are formed
(d) people get pollution - free air to breathe and more oxygen is available
Show Answer
Answer : a
Hints & Solutions
(a) At an altitude of 5400 meters the low atmospheric pressure of $O 2$ will be very 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 fulfill the oxygen requirement of the body, blood has to carry more oxygen to the body tissue and this is done by the increased numbered of RBCs.
