Euchromatin is _____ for RNA polymerases to access and transcribe.

Euchromatin is _____ for RNA polymerases to access and transcribe.

• A. Difficult
• B. Easy
• C. Blocked
• D. Neutral

Answer: (B)

The question tests how chromatin structure affects access of transcription machinery. Euchromatin is the less condensed, open form of chromatin, often with histone acetylation and repositioned nucleosomes that expose promoter and coding regions. This openness makes it easy for RNA polymerase and transcription factors to bind and begin transcription, so genes in euchromatin are typically actively transcribed. If chromatin were tightly packed and inaccessible, transcription would be restricted, which describes heterochromatin rather than euchromatin. Neutral would imply no effect on access, which isn’t the case for euchromatin.

The question tests how chromatin structure affects access of transcription machinery. Euchromatin is the less condensed, open form of chromatin, often with histone acetylation and repositioned nucleosomes that expose promoter and coding regions. This openness makes it easy for RNA polymerase and transcription factors to bind and begin transcription, so genes in euchromatin are typically actively transcribed. If chromatin were tightly packed and inaccessible, transcription would be restricted, which describes heterochromatin rather than euchromatin. Neutral would imply no effect on access, which isn’t the case for euchromatin.