Nucleosomes disaggregate (or "open") to allow transcription and then reaggregate
A) through alternative splicing.
B) by methylation and demethylation.
C) through alternation of nucleotides.
D) by acetylation and deacetylation.
E) through insertion of nucleotides.

Question

Quizplus · Accepted Answer

Nucleosomes are composed of DNA wrapped around histone proteins, and they can block transcription by preventing access to the DNA. Acetylation of the histone proteins can "open" the nucleosomes by loosening the DNA-histone interactions, allowing access to DNA by transcription factors and RNA polymerase. Deacetylation has the opposite effect, promoting nucleosome aggregation and transcriptional repression. Therefore, the answer is D: by acetylation and deacetylation. None of the other options listed have been shown to directly impact nucleosome aggregation or disaggregation.

Nucleosomes Disaggregate (Or "Open") to Allow Transcription and Then Reaggregate