Question: Horizontal gene transfer
Answer Options:
• A) Can accelerate evolution of a species
• B) Can inhibit evolution of a species
• C) Has no role in evolution
• D) Has a role in evolution only if the gene transfer is to a different species
Answer: A) Can accelerate evolution of a species
Question: A strain of penicillin-resistant N. gonorrhoeae that does not have a plasmid is isolated. A lysate made from the bacterium cannot degrade penicillin in an in vitro assay. When a culture of this strain is grown in a solution that contains radioactive penicillin, the amount of penicillin found within cells is less than the amount found within cells from a nonresistant strain. The DNA sequence of the porin gene from the resistant strain does not have any mutations. What is the most likely mechanism of resistance in this strain?
Answer Options:
• A) A mutation in the mtr gene has occurred, resulting in fewer efflux pumps.
• B) A penA nonsense mutation has occurred.
• C) A penA missense mutation has occurred.
• D) The bacterial genome carries the penr gene.
Answer: C) A penA missense mutation has occurred. I will proceed to finish the remaining questions.
Question: Researchers often work with temperature-sensitive mutations ______, because null alleles of these genes create mutants that cannot grow under any conditions.
Answer Options:
• A) That confer antibiotic resistance
• B) In essential genes
• C) That affect colony morphology
• D) That affect metabolism
Answer: B) In essential genes
Question: To produce a mutation in a specific E. coli gene, an engineered fragment of DNA in which sequences from each end of that gene flank an antibiotic resistance gene
Answer Options:
• A) Is transformed into cells and replicates independently of the genomic DNA because it has a centromere.
• B) Is transformed into cells and maintained as a plasmid.
• C) Is introduced into cells and transposes into the bacterial gene.
• D) Is introduced into cells and undergoes homologous recombination with the bacterial gene.
Answer: D) Is introduced into cells and undergoes homologous recombination with the bacterial gene.
Question: Three genes (X, Y, and Z) are in the same region of a bacterial chromosome. To determine the order of these genes, you infect X− Y− Z− cells with a lysate from wild-type cells infected with a generalized transducing phage. When X+ cells are selected, 70% of cells are also Y+ and 5% of cells are Z+. When Y+ cells are selected, 68% of cells are also X+ and 1% are Z+. What is the relative arrangement of the three genes?
Answer Options:
• A) Z is in the middle, but closer to X.
• B) Y is in the middle, but closer to Z.
• C) X is in the middle, but closer to Y.
• D) X is in the middle, but closer to Z.
Answer: C) X is in the middle, but closer to Y.
Question: Complementation studies can be performed in bacteria by
Answer Options:
• A) Gene targeting.
• B) Forming merodiploids with one copy of a bacterial gene on an F′ plasmid.
• C) Forming merodiploids with two copies of a bacterial gene on F′ plasmids.
• D) Forming diploids with two copies of the bacterial chromosome.
Answer: B) Forming merodiploids with one copy of a bacterial gene on an F′ plasmid.
Question: One way N. gonorrhoeae became resistant to penicillin was by acquiring a plasmid that carries the penr penicillin resistance gene, which encodes a protein that
Answer Options:
• A) Allows cells to synthesize penicillin.
• B) Cleaves penicillin to an inactive form.
• C) Pumps penicillin out of the cell.
• D) Attaches penicillin to the cell wall.
Answer: B) Cleaves penicillin to an inactive form.
Question: In transduction, the DNA is being moved between the two cells by
Answer Options:
• A) A third bacterial cell.
• B) A phage.
• C) Transposons.
• D) Membrane-bound transport proteins.
Answer: B) A phage.
Question: A bacteriophage is a
Answer Options:
• A) Bacterium that infects a virus.
• B) Virus that infects a bacterium.
• C) Particle made up of viral nucleic acid surrounded by bacterial protein.
• D) Particle made up of bacterial nucleic acid surrounded by bacterial protein.
Answer: B) Virus that infects a bacterium.
Question: When a bacteriophage carrying bacterial DNA infects a new bacterium,
Answer Options:
• A) The recipient is usually killed.
• B) The recipient keeps the transferred DNA in storage but does not replicate it.
• C) It transfers bacterial DNA from the donor bacterium to the recipient bacterium.
• D) Only viral DNA is transferred to the recipient bacterium.
Answer: C) It transfers bacterial DNA from the donor bacterium to the recipient bacterium.
Question: Match the description with the appropriate term.
Answer Options:
• A) Inversion
• B) Duplication
• C) Deletion
• D) Translocation
• E) Transposable element
Answer: A) Inversion