This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'What is the role of H2 histone? \nSelect and explain. \nA. Stabilize the 30-nm chromatin fiber, B. Central role in the formation of the nucleosome, C. Stabilizes the primary paicle, D. Firmly binds two additional half-turns of DNA', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Types Function H1 histones Stabilize the 30-nm chromatin fiber H2 histones H2A-H2B dimers stabilize the primary paicle and firmly bind two additional half-turns of DNA H3 histones H4 histones (H3-H4)2 tetramer has a central role in the formation of the nucleosome Reference: Harpers illustrated biochemistry 30th edition', 'role': 'assistant'}]