Question 1

Which of the following best describes the function of the TATA box in eukaryotic gene expression?

Accepted Answer

It serves as a binding site for the TATA box-binding protein (TBP), facilitating assembly of the preinitiation complex.

Question 2

During transcription elongation, RNA polymerase synthesizes RNA by adding nucleotides to which end of the growing RNA strand?

Accepted Answer

3' end, using nucleoside triphosphates and releasing pyrophosphate for each nucleotide added: $$	ext{NTP} ightarrow 	ext{NMP} + 	ext{PP}_i$$

Question 3

Which experimental technique is most commonly used to identify the binding sites of transcription factors in the genome?

Accepted Answer

Chromatin immunoprecipitation (ChIP) followed by high-throughput sequencing

Question 4

A mutation in the promoter region of a gene most likely results in which of the following outcomes?

Accepted Answer

Lower levels of mRNA due to reduced transcription initiation

Question 5

Which of the following statements about RNA polymerase II is TRUE?

Accepted Answer

Phosphorylation of its C-terminal domain (CTD) is required for promoter escape and transition to elongation.

Question 6

Which of the following is a key difference between prokaryotic and eukaryotic transcription units?

Accepted Answer

Prokaryotic transcription units contain multiple genes (operons), while eukaryotic transcription units typically contain only one gene.

Question 7

Which of the following best explains how transcription factors that recognize only ~6 base pairs can achieve high specificity in gene regulation?

Accepted Answer

Combinatorial regulation: multiple transcription factors bind to different regulatory elements, creating a unique combination for each gene.

Question 8

Which of the following is a function of nucleosome remodeling complexes in gene expression?

Accepted Answer

They use ATP hydrolysis to move nucleosomes, increasing accessibility of DNA to transcription factors.

Question 9

Steroid hormones regulate gene expression by:

Accepted Answer

Activating transcription factors by releasing them from sequestration in the cytoplasm.

Question 10

Which of the following is a plausible outcome of histone deacetylation near a gene promoter?

Accepted Answer

Chromatin compaction and reduced transcription initiation.

Question 11

A scientist wants to determine the epigenetic state of a specific chromatin region. Which method should they use?

Accepted Answer

Chromatin immunoprecipitation (ChIP) with antibodies to specific histone modifications, followed by sequencing.

Question 12

Which of the following is NOT a mechanism that regulates the activity of transcription factors?

Accepted Answer

Direct methylation of mRNA by transcription factors.

Question 13

Which of the following best describes the role of the mediator complex in transcription initiation?

Accepted Answer

It acts as a co-regulator, integrating signals from transcription factors and facilitating assembly of the preinitiation complex.

Question 14

Which equation correctly represents the energy requirement for nucleosome remodeling complexes?

Accepted Answer

$$	ext{ATP} ightarrow 	ext{ADP} + 	ext{P}_i$$

Question 15

Which of the following is TRUE regarding the termination of transcription by RNA polymerase III?

Accepted Answer

Termination is triggered by a 4-6 U stretch in the RNA, causing back-tracking and dissociation.

Question 16

Which of the following best describes combinatorial regulation of gene expression?

Accepted Answer

The combination of transcription factors bound to promoter, promoter proximal elements, and enhancers determines transcription frequency.

Question 17

Which of the following is a plausible challenge when analyzing protein:DNA interactions in the lab if your protein of interest binds to repetitive DNA?

Accepted Answer

The repetitive nature of the DNA makes it difficult to map binding sites uniquely after sequencing.

Question 18

Which of the following genome editing tools uses a guide RNA to target specific DNA sequences?

Accepted Answer

CRISPR/Cas9

Question 19

Which of the following is a consequence of mutations in splice-site sequences of a eukaryotic gene?

Accepted Answer

Aberrantly spliced mRNA, potentially resulting in unstable or inactive protein products.

Gene Expression: Mechanisms and Regulation in Eukaryotes and Prokaryotes

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