Assertion :A sigmoid curve is obtained when percentage saturation of haemoglobin with O2 is plotted against the PO2. Reason: Every 100 mL of oxygenated blood can deliver around 5ml of O2 to the tissues under normal physiological conditions.
Both the statements given in the question are correct but the statement in the reason does not explain the statement in the assertion.
So, the correct answer is 'Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion'.