Histone acetylation is associated with which chromatin state?

Histone acetylation is associated with which chromatin state?

• A. Euchromatin
• B. Heterochromatin
• C. Nucleosome
• D. Chromatin fiber

Answer: (A)

Histone acetylation neutralizes positive charges on histone tails, reducing their grip on the negatively charged DNA. This loosens the nucleosome-DNA interaction and opens up the chromatin, making it more accessible to transcription machinery. That open, accessible state is euchromatin, which is associated with active gene expression. In contrast, heterochromatin is tightly packed and transcriptionally silent, reflecting a largely deacetylated, condensed state. Nucleosomes and chromatin fibers are structural units, but acetylation specifically shifts chromatin toward the open, active form. So histone acetylation is linked to euchromatin.

Histone acetylation neutralizes positive charges on histone tails, reducing their grip on the negatively charged DNA. This loosens the nucleosome-DNA interaction and opens up the chromatin, making it more accessible to transcription machinery. That open, accessible state is euchromatin, which is associated with active gene expression. In contrast, heterochromatin is tightly packed and transcriptionally silent, reflecting a largely deacetylated, condensed state. Nucleosomes and chromatin fibers are structural units, but acetylation specifically shifts chromatin toward the open, active form. So histone acetylation is linked to euchromatin.