複選題
18. Which of the following characteristics of histones are right? (A) H1 histones are the ones least tightly bound to chromatin (B) H3 and H4 histones form a tetramer containing two molecules of each (H3-H4)2 (C) H2A and H2B histones form dimers (H2A-H2B). (D) H2A, H2B, H3, and H4 are core histones of nucleosomes (E) H1, H2, H3, and H4 histones associate to form the histone octamer.