Question
Biology Question on Exchange Of Gases
At high altitudes, RBC of human blood will
A
Increase in number
B
Decrease in number
C
Decrease in size
D
Increase in size
Answer
Increase in number
Explanation
Solution
At high altitude composition of air remains almost same as that of sea level, but density (barometric pressure) of air gradually decreases due to which arterial pO is also decreased (hypoxemia).A high altitude shows complex conditions to which human body has to acclimatize. Number of red blood cells per unit volume of blood is likely to be higher in a person living at high altitudes. This is in response to the air being less dense at high altitude and number of red blood cells is needed to trap O from rarefied air having lowp O (partial pressure of oxygen).