Question 1

Which of the following best describes a spontaneous mutation in bacteria?

Accepted Answer

A mutation resulting from errors in DNA replication occurring naturally.

Question 2

A scientist observes a bacterial strain that has acquired resistance to an antibiotic after exposure to a chemical mutagen. Which of the following best explains the role of the mutagen?

Accepted Answer

The mutagen increases the rate of mutation, potentially resulting in antibiotic resistance.

Question 3

Which of the following statements about horizontal gene transfer is correct?

Accepted Answer

Horizontal gene transfer allows bacteria to share genes independently of cell division.

Question 4

A bacterium lacking a fertility plasmid (F-) comes into contact with a bacterium possessing an F plasmid (F+). What is the most likely outcome?

Accepted Answer

The F- bacterium will receive a copy of the F plasmid via a pilus.

Question 5

Which of the following best describes the process of transformation in bacteria?

Accepted Answer

Uptake of exogenous DNA from the environment by competent cells.

Question 6

Fredrick Griffith's experiment with Streptococcus pneumoniae demonstrated which genetic process?

Accepted Answer

Transformation

Question 7

Which of the following is TRUE regarding R plasmids?

Accepted Answer

R plasmids are extrachromosomal DNA that confer antibiotic resistance.

Question 8

A temperate phage infects a bacterial cell. Which of the following best describes what happens during the lysogenic cycle?

Accepted Answer

The phage DNA integrates into the host genome as a prophage.

Question 9

Which of the following best distinguishes generalized transduction from specialized transduction?

Accepted Answer

Generalized transduction involves transfer of any bacterial gene, while specialized transduction transfers only specific genes adjacent to the prophage.

Question 10

Which of the following is a biological mutagen?

Accepted Answer

Transposons

Question 11

A bacteriophage packages a fragment of host DNA instead of its own DNA during assembly. This is an example of:

Accepted Answer

Generalized transduction

Question 12

Which of the following statements about transposons is correct?

Accepted Answer

Transposons are segments of DNA that can move within the genome.

Question 13

In prokaryotes, which class of transposons is more common?

Accepted Answer

DNA transposons

Question 14

A carcinogen is best defined as:

Accepted Answer

A mutagen that causes a rate of mutation promoting cancer development.

Question 15

Which of the following is NOT a mechanism of horizontal gene transfer in bacteria?

Accepted Answer

Vertical gene transfer

Question 16

A medical researcher uses plasmids to create a bacterial cell line that produces insulin. This is an example of:

Accepted Answer

Using plasmids for medical applications.

Question 17

Which of the following best describes competent cells?

Accepted Answer

Cells that can be transformed by taking up DNA from their environment.

Question 18

A high-frequency recombination (Hfr) strain is formed when:

Accepted Answer

The fertility plasmid merges with the bacterial chromosome.

Question 19

Which of the following is TRUE about temperate phages?

Accepted Answer

They can undergo both the lytic and lysogenic cycles.

Question 20

A bacterial cell is exposed to X-rays, which induce DNA damage. This is an example of:

Accepted Answer

Physical mutagenesis

Genetic Variation and Horizontal Gene Transfer in Microbiology

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