Question

Mammals native to high altitudes have haemoglobins of greater oxygen affinity than low altitude forms because

• A. They need more oxygen than their low altitude counter-parts.
• B. The haemoglobin allows extraction of oxygen from environment that is poor in oxygen (high altitudes) relative to low altitudes.
• C. They have less number of erythrocytes than their counterparts on low altitudes and increased oxygen affinity balances the reduced percentage of erythrocytes.
• D. None of the statements are correct.

Answer 1

The correct option is B The haemoglobin allows extraction of oxygen from environment that is poor in oxygen (high altitudes) relative to low altitudes.

At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems, this results into hypoxia to human population, who are from sea level. The physiological and genetic adaptations in these people involve massive modification in the oxygen transport system of the blood, especially molecular changes in the structure and functions hemoglobin, allowing it to extract oxygen from environment, that is poor in oxygen (high altitudes) relative to low altitudes. This adaptation is associated with better developmental patterns, such as high birth weight, increased lung volumes, increased breathing and higher resting metabolism.