Multiple choice

People who live at high altitudes have rosy cheeks because

  1. haemoglobin has an increased binding affinity for oxygen

  2. RBCs and haemoglobin concentration becomes considerably above the average in response to lowered oxygen pressure

  3. rate of capillary circulation increases in the skin

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

At high altitudes, lower oxygen pressure stimulates increased erythropoietin production, causing polycythemia - elevated RBC and hemoglobin concentration. This gives skin a rosy appearance. Option A is incorrect because hemoglobin affinity actually decreases (right shift of oxygen dissociation curve) to facilitate oxygen release to tissues. Option C is not the primary physiological adaptation.

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