Question 1

Which of the following best describes the initial step in homologous recombination repair of a double-strand DNA break?

Accepted Answer

The 5' ends are digested to create 3' overhangs.

Question 2

A patient’s cells are unable to repair double-strand breaks during the G1 phase. Which repair pathway is most likely defective?

Accepted Answer

Nonhomologous end joining

Question 3

Which of the following is a potential consequence of nonhomologous end joining (NHEJ) repair of double-strand breaks?

Accepted Answer

Loss of several base pairs at the repair site

Question 4

Transposable elements can disrupt gene function by inserting into which of the following regions?

Accepted Answer

Both protein-coding regions and promoters

Question 5

In the Ac-Ds system in maize, what is the role of the Ac element?

Accepted Answer

It provides transposase necessary for Ds movement.

Question 6

Which of the following best explains why some maize kernels are speckled in color?

Accepted Answer

Excision of Ds from the C gene during kernel development

Question 7

Which of the following statements about retrotransposons is correct?

Accepted Answer

They require reverse transcriptase for movement.

Question 8

A scientist observes that a bacterial strain has acquired resistance to multiple antibiotics. Which genetic element is most likely responsible for this phenomenon?

Accepted Answer

Large bacterial transposons

Question 9

Which of the following is a key difference between autonomous and nonautonomous transposable elements?

Accepted Answer

Nonautonomous elements cannot move without enzymes provided by autonomous elements.

Question 10

Which of the following best describes the function of the SWI/SNF complex in eukaryotic cells?

Accepted Answer

It remodels chromatin to make DNA accessible for transcription.

Question 11

Which histone modification is generally associated with increased transcriptional activity?

Accepted Answer

Acetylation of histone tails

Question 12

DNA methylation in vertebrates typically leads to which of the following outcomes?

Accepted Answer

Suppression of gene expression

Question 13

Which of the following is a cis-acting regulatory element that can increase the transcription of a gene from a distance?

Accepted Answer

Enhancer

Question 14

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

Accepted Answer

Initiation of transcription

Question 15

Which of the following best describes the role of general transcription factors in eukaryotic transcription?

Accepted Answer

They are required for the assembly of the pre-initiation complex at the promoter.

Question 16

In the yeast GAL gene system, what is the function of the Gal4 protein?

Accepted Answer

It acts as an activator by binding to UASG sequences.

Question 17

Alternative splicing of pre-mRNA allows for which of the following?

Accepted Answer

Generation of multiple protein isoforms from a single gene

Question 18

Which of the following mechanisms is used by the cell to regulate the steady-state level of mRNA?

Accepted Answer

mRNA degradation pathways

Question 19

The p53 protein is rapidly degraded in normal cells. Which protein is responsible for tagging p53 for degradation?

Accepted Answer

Mdm2

Question 20

Which of the following best explains why LINEs and SINEs are significant in the human genome?

Accepted Answer

They make up a large portion of the genome and contribute to genetic variability.

DNA Repair, Transposable Elements, and Eukaryotic Gene Regulation

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