The oxygen hemoglobin dissociation curve is sigmoid because:
A i.e. Binding of one oxygen molecule increases the affinity of binding other 0, molecule
Binding of one oxygen molecule increases the affinity of binding other 0, molecules
Binding of one oxygen molecule decrease the affinity of binding other 02 molecules
Oxygen affinity of Hemoglobin decreases when the pH of blood falls
Binding of oxygen to hemoglobin reduces the affinity of Hb for CO2