Which chromatin state is typically gene-poor and transcriptionally silent due to dense packing?

Which chromatin state is typically gene-poor and transcriptionally silent due to dense packing?

• A. Euchromatin
• B. Heterochromatin
• C. Nucleosome
• D. DNA

Answer: (B)

Gene expression is influenced by how tightly DNA is packed into chromatin. In the densely packed form, known as heterochromatin, DNA is wrapped up and compacted so transcription factors and RNA polymerase can’t access promoters easily, leaving these regions gene-poor and transcriptionally silent. This compact state effectively shuts down gene activity in those areas. By contrast, more open chromatin, called euchromatin, tends to be gene-rich and actively transcribed. Nucleosomes are the basic units of chromatin, and DNA is the genetic material itself; neither describes a chromatin state.

Gene expression is influenced by how tightly DNA is packed into chromatin. In the densely packed form, known as heterochromatin, DNA is wrapped up and compacted so transcription factors and RNA polymerase can’t access promoters easily, leaving these regions gene-poor and transcriptionally silent. This compact state effectively shuts down gene activity in those areas. By contrast, more open chromatin, called euchromatin, tends to be gene-rich and actively transcribed. Nucleosomes are the basic units of chromatin, and DNA is the genetic material itself; neither describes a chromatin state.