Question 1

Which of the following best describes a missense mutation in a bacterial gene?

Accepted Answer

A mutation that changes one amino acid in the protein sequence, potentially altering protein function.

Question 2

Which DNA repair system in bacteria is considered a 'last resort' and is characterized by a high error rate?

Accepted Answer

SOS response system involving DNA Pol IV and V

Question 3

A researcher introduces a plasmid carrying a wild-type gene into a mutant bacterial strain lacking that gene. The mutant phenotype is restored. What is this phenomenon called?

Accepted Answer

Complementation in trans

Question 4

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

Accepted Answer

Binary fission

Question 5

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids can carry antibiotic resistance genes and replicate independently of the chromosome.

Question 6

Which of the following best describes the process of generalized transduction?

Accepted Answer

Transfer of random fragments of host DNA by a lytic bacteriophage.

Question 7

A frameshift mutation is most likely to result from which of the following?

Accepted Answer

Addition or deletion of one or two nucleotides

Question 8

Which of the following is a function of the RecA protein in bacteria?

Accepted Answer

Mediates homologous recombination and DNA repair

Question 9

Which of the following best explains why ethidium bromide is a mutagen?

Accepted Answer

It intercalates between DNA base pairs, causing insertions or deletions during replication.

Question 10

Which of the following is a key difference between F+ and Hfr strains of E. coli?

Accepted Answer

Hfr strains have the F plasmid integrated into the chromosome, allowing transfer of chromosomal genes during conjugation.

Question 11

Which of the following best describes a compound transposon?

Accepted Answer

Two insertion sequences flanking additional genes, moving as a unit

Question 12

A bacterial cell is exposed to UV light, resulting in DNA damage. Which repair mechanism is most likely to be activated first?

Accepted Answer

Excision repair enzymes

Question 13

Which of the following is a real-world example of transformation in bacteria?

Accepted Answer

Uptake of DNA from dead smooth Streptococcus pneumoniae by live rough cells, making them pathogenic

Question 14

Which of the following is a property of self-transmissible plasmids?

Accepted Answer

They encode both Dtr (DNA transfer and replication) and Mpf (mating pair formation) functions.

Question 15

Which of the following best describes the role of the sex pilus in bacterial conjugation?

Accepted Answer

It forms a channel for DNA transfer between donor and recipient cells.

Question 16

Which of the following is a likely outcome when a transposon inserts into a protein-coding gene?

Accepted Answer

The gene's function is disrupted, potentially causing a loss-of-function mutation.

Question 17

Which of the following is a common use of transposons in bacterial genetics research?

Accepted Answer

To create a collection of random gene knockouts for functional studies.

Question 18

Which of the following best describes the difference between orthologs and paralogs?

Accepted Answer

Orthologs are genes with the same function in different species, while paralogs are duplicated genes within a species that may diverge in function.

Question 19

Which of the following is a key feature of rolling circle replication during conjugation?

Accepted Answer

A single DNA strand is nicked and transferred to the recipient, where it is replicated.

Question 20

Which of the following is a likely indicator of horizontal gene transfer when analyzing bacterial genomes?

Accepted Answer

Genes with high sequence similarity found in distant phylogenetic groups.

Genetics of Bacteria and Archaea: Mutation, Recombination, and Gene Transfer

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