Assertion : A rise in `PCO_(2), H^(+)` ions and temperature shifts the `HbO_(2)` dissociation curve to right.
Reason : A rise in `PCO_(2)` or fall in pH decreases oxygen affinity for haemoglobin.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true and reason is not the correct explanation of assertion
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

A

Explanation

A shift to the right of oxygen dissociation curve indicates dissociation of oxygen from haemoglobin. In the tissues, low `pO_(2)`, high `pCO_(2)`, high `H^(+)` concentration (low pH or acidity) and higher temperature favour dissociation of oxygen from the oxyhaemoglobin.