Question 1

Which of the following best describes the role of enhancer sequences in eukaryotic gene regulation?

Accepted Answer

Enhancer sequences are DNA elements that activate transcription by binding activator proteins and facilitating the assembly of the transcriptional machinery.

Question 2

Which modification is associated with euchromatin and increased gene expression?

Accepted Answer

Acetylation of H3K4

Question 3

In eukaryotes, which process occurs in the nucleus and is essential for producing mature mRNA?

Accepted Answer

Pre-mRNA processing, including 5' capping, intron splicing, and 3' polyadenylation

Question 4

Which of the following is NOT a function of the 5' cap added to eukaryotic pre-mRNA?

Accepted Answer

Initiating DNA replication

Question 5

A mutation prevents polyadenylation of a eukaryotic mRNA. Which outcome is most likely?

Accepted Answer

The mRNA will be rapidly degraded and poorly translated.

Question 6

Which equation correctly represents the central dogma of molecular biology?

Accepted Answer

$$DNA \rightarrow RNA \rightarrow Protein$$

Question 7

Which of the following statements about introns and exons is correct?

Accepted Answer

Introns are non-coding regions removed from pre-mRNA, while exons are coding regions retained in mature mRNA.

Question 8

Alternative splicing allows a single gene to:

Accepted Answer

Produce multiple distinct mRNA transcripts and protein isoforms.

Question 9

Which process is responsible for the removal of introns from pre-mRNA in most eukaryotic genes?

Accepted Answer

Spliceosome-mediated splicing

Question 10

A researcher isolates a mature mRNA and finds it lacks a 5' cap. Which of the following is most likely to occur?

Accepted Answer

The mRNA will be rapidly degraded and poorly translated.

Question 11

Which of the following best explains why chromatin-based regulation is considered an epigenetic process?

Accepted Answer

It involves heritable changes in gene expression without altering the DNA sequence.

Question 12

Which of the following is a real-world example of alternative splicing producing different proteins from the same gene?

Accepted Answer

The CT/CGRP gene producing calcitonin in thyroid cells and CGRP in neuronal cells.

Question 13

Which enzyme is responsible for digesting the residual uncapped transcript during eukaryotic transcription termination, as described by the torpedo model?

Accepted Answer

RNase XRN2

Question 14

Which of the following statements about self-splicing introns is correct?

Accepted Answer

Self-splicing introns can catalyze their own removal without protein enzymes.

Question 15

Which of the following modifications is commonly found in human tRNAs and is important for their function?

Accepted Answer

Pseudouridine

Question 16

Which of the following best describes the difference between euchromatin and heterochromatin?

Accepted Answer

Euchromatin is loosely packed and transcriptionally active; heterochromatin is highly compacted and inactive.

Question 17

A gene contains three exons and two introns. If alternative splicing occurs, how many different mature mRNAs could theoretically be produced?

Accepted Answer

$$4$$

Question 18

Which of the following is a direct consequence of chromatin compaction on gene expression?

Accepted Answer

Decreased accessibility of transcription factors to target DNA sequences

Question 19

Which of the following steps is unique to eukaryotic gene expression and does NOT occur in prokaryotes?

Accepted Answer

Post-transcriptional processing of pre-mRNA, including splicing and polyadenylation

Question 20

Which of the following best explains why some eukaryotic transcripts, such as histone mRNAs, do not undergo polyadenylation?

Accepted Answer

They have unique 3' end structures that allow for stability and translation without a poly(A) tail.

Regulation and Processing of Eukaryotic Gene Expression

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