Question

Why does the red blood cell count of humans increase when they remain at high altitudes?
A Haemoglobin is not saturated with oxygen in the lungs.
B The partial pressure of oxygen is higher.
C The percentage of oxygen in the air has decreased.
D There is more carbon dioxide, increasing the Bohr effect

Answer 1

C.Its because the higher the altitude, the less oxygen there is in the air. The percentage of oxygen in the air has decreased.

Answer 2

Answer is C Because
Red Blood cells contain haemoglobin which is what the oxygen binds with to form oxyhaemoglobin which is then transported to the different cells around the body. Oxygen bonds with the haemoglobin when it is at high partial pressure and then is released when there is a lower partial pressure of oxygen. At high altitudes there is lower atmospheric pressure of oxygen. This means that the current number of red blood cells in the body cannot meet the cells demands for oxygen. Due to the lower partial pressure of oxygen a process called polycythemia occurs, which is an increase in the bodies red blood cell count. The body increases its red blood cell count because this means there is more haemoglobin available to bond with oxygen molecules meaning more oxygen can be transported to the cells in the body, therefore helping to meet the oxygen demands of the body even with less oxygen in the air.