<prompt> At the physiological pH the DNA molecules are:Positively chargedAmphipathicNegatively chargedNeutral  <response>: DNA molecules are negatively charged. Histones, along with positively charged ions such as Mg2, help neutralize the negatively charged DNA phosphate groups. Histone proteins possess an unusually high content of basic amino acids arginine and lysine that, through ionic bonds, facilitate interaction with the negatively charged DNA. Ref: Biochemistry By Richard A. Harvey Ph. D., Richard A. Harvey, Denise R. Ferrier, 2011, Page 409. 