$$\text{Steady-state mRNA} = \text{Rate of transcription} - \text{Rate of degradation}$$

Question 1

Which structural feature of eukaryotic chromosomes is most directly responsible for the spatial separation of transcription and translation?

Accepted Answer

Chromosome territories within the nucleus

Question 2

In the context of chromatin remodeling, which modification is most closely associated with gene activation?

Accepted Answer

Histone acetylation

Question 3

A gene is found to be heavily methylated at its CpG island in the promoter region. What is the most likely effect on its expression?

Accepted Answer

Decreased transcription

Question 4

Which equation best describes the steady-state level of mRNA in a cell?

Accepted Answer

$$	ext{Steady-state mRNA} = 	ext{Rate of transcription} - 	ext{Rate of degradation}$$

Question 5

Which histone modification is most likely to result in a more open chromatin structure, facilitating transcription?

Accepted Answer

Acetylation of lysine residues

Question 6

Which of the following is a cis-acting element that can increase transcription rates and may be located far from the gene it regulates?

Accepted Answer

Enhancer

Question 7

A mutation in the TATA box of a gene’s promoter is most likely to affect which process?

Accepted Answer

Binding of RNA polymerase II

Question 8

Which motif in transcription factors is characterized by two adjacent α-helices separated by a turn, enabling DNA binding?

Accepted Answer

Helix-turn-helix

Question 9

What is the primary function of the SWI/SNF chromatin remodeling complex?

Accepted Answer

Repositioning nucleosomes to expose DNA regions

Question 10

Which pathway is most likely to degrade mRNA containing a premature stop codon?

Accepted Answer

Nonsense-mediated decay

Question 11

Which equation represents the half-life ($$t_{1/2}) of $$mRNA if the degradation follows first-order kinetics?

Accepted Answer

$$t_{1/2} = \frac{\ln 2}{k}$$

Question 12

Which of the following best describes the effect of histone deacetylase (HDAC) activity on gene expression?

Accepted Answer

Decreases transcription by tightening chromatin

Question 13

Which of the following is a real-world application of RNA interference (RNAi) technology?

Accepted Answer

Reducing the expression of dominant mutant gene products

Question 14

Which protein complex is responsible for degrading ubiquitinated proteins in eukaryotic cells?

Accepted Answer

Proteasome

Question 15

Which of the following is NOT a mechanism by which chromatin remodeling complexes alter nucleosome structure?

Accepted Answer

Directly methylating mRNA

Question 16

Which type of alternative splicing can generate mutually exclusive protein isoforms from a single gene?

Accepted Answer

Mutually exclusive exons

Question 17

Which domain of a transcription factor is responsible for activating or repressing transcription through protein-protein interactions?

Accepted Answer

Trans-activating domain

Question 18

Which of the following best explains why eukaryotic gene regulation is more complex than prokaryotic gene regulation?

Accepted Answer

Eukaryotes have spatial separation of transcription and translation

Question 19

Which of the following is a characteristic feature of the zinc finger motif in transcription factors?

Accepted Answer

Clusters of two cysteines and two histidines binding zinc atoms

Question 20

A cell is treated with 5-azacytidine, a base analog that cannot be methylated. What is the most likely outcome for gene expression?

Accepted Answer

Genes normally silenced may become expressed

CH17&18: Regulation of Gene Expression in Eukaryotes: Mechanisms and Molecular Features

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