what is an example of a histone in bio
Examples of epigenetics. Epigenetic changes alter the physical structure of DNA. One example of an epigenetic change is DNA methylation â the addition of a methyl group, or a chemical cap, to part of the DNA molecule, which prevents certain genes from being expressed. Another example is histone modification. Histones are proteins that DNA wraps around. (Without histones, DNA would be too long to fit inside cells.) If histones squeeze DNA tightly, the DNA cannot be read by the cell. Modifications that relax the histones can make the DNA accessible to proteins that read genes.