Question

Question 3 Mountain climbers may have difficulty at high elevations because: O A More carbon dioxide occurs at higher altitudes B The concentration of all elements of the air is lower at higher el C Cooler temperatures restrict the metabolic activity of carbon d o untains O D The partial pressure of oxygen is lower at higher elevations Unanswered

Answer 1

D. The partial pressure of oxygen is lower at higher elevations.

(At sea level the partial pressure of oxygen (the amount of oxygen available for respiration) is much higher in comparison to the increasing altitude. With increasing altitude the body’s oxygen requirement does not alter and even at moderate altitude hypoxia (oxygen starvation) is common. The symptoms of low oxygen at high altitudes are responsible for the mountain sickness, however, within a few days or weeks, our body gets acclimatized to oxygen starvation by increasing the hematocrit levels. Thus various physiological symptoms like nausea, the headache of high altitude are related to the low partial pressure of oxygen and the inability to supply sufficient oxygen at the tissue level)