Final answer:
Chromatin remodeling can be done through histone acetylation and histone methylation.
Step-by-step explanation:
Chromatin remodeling by chemical modification of histones can be done in two ways: histone acetylation and histone methylation.
1. Histone acetylation involves the addition of acetyl groups to lysine residues on the histone proteins. This modification tends to unwind nucleosomes and open the underlying DNA for transcription.
2. Histone methylation involves the addition of methyl groups to lysine or arginine residues on the histone proteins. Methylation can either open or close DNA for transcription, depending on the specific site and degree of methylation.