This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Biochemistry
In sickle cell anaemia, sickle shapes occur due to polymerization of 
Select and explain. 
A. Oxyhemoglobin, B. Deoxyhemoglobin, C. Methoxyglobin, D. Cyanohemoglobin
B: Deoxyhemoglobin
Answer: B: Deoxyhemoglobin 
Explanation: The substitution of hydrophilic glutamic acid by hydrophobic valine causes a localized stickiness on the surface of the molecule. The deoxygenated HbS may be depicted with a protrusion on one side and a cavity on the other side, so that many molecules can adhere and polymerize.Ref: D M Vasudevan 7th edition Page no: 291,292