A graph of the oxygen-haemoglobin dissociation curve shows a standard sigmoid curve (Curve A) and a second curve (Curve B) which is shifted to the right relative to Curve A. Which of the following sets of physiological conditions in the blood would cause the shift from Curve A to Curve B?

Step-by-step solution

A rightward shift in the oxygen-haemoglobin dissociation curve indicates a decrease in the affinity of haemoglobin for oxygen, which facilitates the unloading of oxygen. According to NCERT, the conditions that favour dissociation of oxygen from oxyhaemoglobin (a right shift) are low pO₂ , high pCO₂ , high H ^+ concentration (which means low pH), and higher temperature. These conditions are typically found in the systemic tissues. Low pCO₂ , high pH (low H ^+ ), and low temperature would cause a left shift (increase