This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
False statement about hemoglobin structure? 
Select and explain. 
A. Hb has 2 polypeptide, B. Iron is present in ferrous state, C. Hb structurally similar to myoglobin, D. Ferrous ions are in porphyrin rings
A: Hb has 2 polypeptide
Answer: A: Hb has 2 polypeptide 
Explanation: Each hemoglobin molecule is made up of:- (i) Non-protein part, i.e. heme; and (ii) Globin, which has 4 polypeptide chains (2 pairs of similar polypeptide chains).
Iron of hemoglobin is in the ferrous state which lies in the center of the porphyrin ring.
Myoglobin and the β-subunits of hemoglobin share almost identical structures.