Identity how the addition of acetyl groups to stones leads to a weaker association of DNA in nucleosomes. a Positively charged histones are able to interact with negatively charged phosphate groups of the DNA backbone. Addition of acetyl groups to histone heads weaken this interaction by reducing the positive charge on histones b Negatively charged histones are able to interact with positively charged phosphate groups of the DNA backbone. Addition of acetyl groups to historietails weakens this interaction by reducing the negative charge on histones c Positively charged histones are able to interact with negatively charged phosphate groups of the DNA backbone. Addition of acetyl groups to histone tails weakens this interaction by reducing the positive charge on histones. d Negatively charged histones are able to interact with positively charged phosphate groups of the DNA backbone. Addition of acetyl groups to histone heads weakens this interaction by reducing the negative charge on histones