Physiology The sigmoid nature of Hb-O2 dissociation curve is because of A Binding of one O2 molecule increase the affinity for the next O2 molecule B Alpha chain has more affinity for O2 than beta chain C Beta chain has more affinity for O2 than alpha chain D Hemoglobin is acidic in nature 💡 Explanation The sigmoid nature of Hb-O2 dissociation curve is because of ✓ Correct Answer: A. Binding of one O2 molecule increase the affinity for the next O2 molecule