Final answer:
The concentration of 2,3-bisphosphoglycerate (2,3-BPG) increases at high altitudes to facilitate the release of oxygen from haemoglobin to the body's tissues. This increase in BPG levels enables better oxygen delivery despite the lower oxygen availability in high-altitude environments.
Step-by-step explanation:
How does 2,3-bisphosphoglycerate (2,3-BPG) adapt during exposure to high altitudes? The correct answer is b) Its concentration increases.
At high altitudes, where the partial pressure of oxygen is low, the body compensates by increasing the production of 2,3-bisphosphoglycerate (BPG) in erythrocytes. This adaptation is crucial as BPG lowers the affinity of haemoglobin for oxygen, facilitating the release of oxygen to the tissues. In this way, tissues can obtain the oxygen they need despite the lower availability of oxygen in the environment.
An increased concentration of BPG promotes the disassociation of oxygen from haemoglobin, which is beneficial in high-altitude conditions because it helps in oxygen delivery to the tissues. Moreover, a higher level of BPG causes a rightward shift in the oxygen-haemoglobin dissociation curve, indicating that more oxygen is released from hemoglobin at the same partial pressure of oxygen. As a result, this physiological adaptation helps to maintain adequate tissue oxygenation when the oxygen level is inherently lower at high altitudes.