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
[{'content': 'SCD is caused by a recessive, single-nucleotide mutation in the beta globin gene of Hgb. All of the following are TRUE about Sickle cell disease, EXCEPT: \nSelect and explain. \nA. Single nucleotide change results in change of Glutamine to Valine, B. Sticky patch is generated as a result of replacement of a non polar residue with a polar residue, C. HbS confers resistance against malaria in heterozygotes, D. RFLP results from a single base change', 'role': 'user'}, {'content': 'Answer: B \nExplanation: When the sickle Hgb unloads its O2, the normal conformational change exposes the valine at position 6 to the surface creating a "hydrophobic (sticky) patch". The hydrophobic patch on one deoxygenated Hgb molecule can interact with the hydrophobic patch on a second Hgb molecule, creating stiff Hgb polymers. These internal polymers cause the RBC to stiffen and adopt abnormal shapes, including a crescent or "sickle" shape that gives the disease its name. Ref: Poeus M., Mantanona T. (2012). Chapter 14. Blood. In L.W. Janson, M.E. Tischler (Eds), The Big Picture: Medical Biochemistry.', 'role': 'assistant'}]