Question 1

Which of the following is a direct effect of histone acetylation on chromatin structure and gene expression?

Accepted Answer

It decreases the positive charge on histone lysines, loosening DNA-histone binding and promoting transcription.

Question 2

A researcher treats cells with a histone deacetylase (HDAC) inhibitor. What is the most likely outcome for gene expression?

Accepted Answer

Transcription will increase due to more relaxed chromatin.

Question 3

Which DNA modification is most commonly associated with transcriptional repression in eukaryotes?

Accepted Answer

DNA methylation

Question 4

In humans, only the paternal allele of IGF-2 is expressed. Which chromatin modification is most likely responsible for this phenomenon?

Accepted Answer

DNA methylation of the maternal allele

Question 5

Which of the following best describes the role of enhancers in eukaryotic transcription?

Accepted Answer

Enhancers can function at variable distances and orientations relative to the promoter to increase transcription.

Question 6

A mutation moves the promoter of a gene far away from its coding sequence. What is the most likely effect on transcription?

Accepted Answer

Transcription will decrease or be abolished because the promoter must be near the transcription start site.

Question 7

Which equation best represents the relationship between mRNA degradation rate ($$k_{deg}) $$and steady-state mRNA concentration ($$[mRNA]_{ss}) if $$the synthesis rate is $$k_{syn}$$?

Accepted Answer

$$[mRNA]_{ss} = k_{syn} / k_{deg}$$

Question 8

Which of the following would you expect to be abundant in lamina-associated domains (LADs) of the nucleus?

Accepted Answer

Methylated DNA and repressed genes

Question 9

A tumor cell is treated with a proteasome inhibitor under normoxic conditions. What is the most likely effect on HIF-1a and VEGF levels?

Accepted Answer

HIF-1a would accumulate and VEGF levels would increase.

Question 10

Which of the following is NOT a level at which eukaryotic gene expression can be regulated?

Accepted Answer

Protein folding control

Question 11

A cell is exposed to hypoxic conditions. Which sequence of events best describes the regulation of VEGF expression?

Accepted Answer

HIF-1a accumulates, binds to the VEGF promoter, and increases VEGF transcription.

Question 12

Which of the following best explains how transcription factors bound to enhancers can promote transcription?

Accepted Answer

They facilitate recruitment of RNA polymerase and alter chromatin structure.

Question 13

Which of the following is an example of combinatorial regulation of transcription?

Accepted Answer

Multiple transcription factors and chromatin modifications working together to regulate gene expression.

Question 14

Which experiment would best test whether hypoxia/HIF-1a-induced VEGF is required for tumor angiogenesis and growth?

Accepted Answer

Using mouse tumors expressing dominant negative HIF-1a and measuring blood vessel formation and tumor size.

Question 15

Which of the following statements about chromatin remodeling is correct?

Accepted Answer

Chromatin remodelers move nucleosomes to expose DNA for transcription.

Question 16

If a gene is located in a transcriptionally repressed topologically associated domain (TAD), which modification is most likely present?

Accepted Answer

High levels of DNA methylation

Question 17

Which of the following is a consequence of DNA rearrangements in eukaryotic gene regulation?

Accepted Answer

Generation of antibody diversity in immune cells

Question 18

Which of the following is a plausible effect of environmental conditions on regulatory transcription factors?

Accepted Answer

Hypoxia increases HIF-1a levels, altering gene expression.

Question 19

Which of the following is true regarding the position of enhancers relative to the genes they regulate?

Accepted Answer

Enhancers can be located upstream, downstream, or within introns and still regulate transcription.

Question 20

Which of the following best describes the effect of histone deacetylation on gene expression?

Accepted Answer

It decreases transcription by condensing chromatin.

Control of Transcription in Eukaryotes (Chapter 17 Study Notes)

Guida di studio - Domande di pratica

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