Ch.8 Transcriptional Control of Gene Expression

One TFII complex has helicase activity. What is the role of the helicase?

The helicase unwinds the DNA double helix, allowing access for RNA polymerase to transcribe the DNA into RNA.

Which of the following would be most likely to recruit an HDAC to deacetylate histones?

A transcription factor with repressive function.

Two common epigenetic modifications of chromatin are histone H3 K9 methylation and K27 methylation (H3K9me and H3K27me). What does the presence of these marks usually indicate?

They typically indicate gene silencing and chromatin condensation, leading to repression of transcription.

Which statement about RNA polymerases (RNAP) is true? A. RNAP I transcribes tRNA genes. B.RNAP II transcribes rRNA genes. C.RNAP III transcribes protein coding genes. D.RNAP I, II, and III are evolutionarily related (homologous) to E. coli RNAP. E.Transcription initiation by RNAP I, II, and III are all highly regulated.

The correct statement is E. Transcription initiation by RNAP I, II, and III is highly regulated to ensure proper gene expression.

What is the collective role of general transcription factors (GTFs) in eukaryotic transcription initiation?

GTFs assemble at the core promoter to recruit RNA Polymerase II, forming the pre-initiation complex and facilitating the start of transcription.

What is the primary function of RNA Polymerase II (RNAP II) in eukaryotes?

RNAP II primarily transcribes protein-coding genes into messenger RNA (mRNA) precursors, and also transcribes some small RNA genes.

What is the main difference between a gene promoter and an enhancer in the context of gene regulation?

A promoter is a DNA sequence located immediately upstream of a gene where the transcription machinery assembles to initiate transcription. An enhancer is a DNA sequence that can be located far from a gene (upstream, downstream, or even within an intron) and binds transcriptional activators to boost gene expression.

What is the primary function of RNA Polymerase I (RNAP I) in eukaryotes?

RNAP I transcribes genes for ribosomal RNA (rRNA) precursors.

What is the primary function of RNA Polymerase III (RNAP III) in eukaryotes?

RNAP III transcribes genes for transfer RNA (tRNA), 5S ribosomal RNA (rRNA), and a variety of other small RNAs.