Question 1

Hfr strains of Escherichia coli

Accepted Answer

A)  do not possess an F factor. 
B)  have the F factor as a plasmid. 
C)  have an integrated F factor. 
D)  transfer the complete F factor to recipient cells at a high frequency. 
A)  do not possess an F factor. 
B)  have the F factor as a plasmid. 
C)  have an integrated F factor. 
D)  transfer the complete F factor to recipient cells at a high frequency.

Question 2

Consider the following experiment. First, large populations of two mutant strains of Escherichia coli are mixed, each requiring a different, single amino acid. After plating them onto a minimal medium, 45 colonies grew. Which of the following may explain this result?

Accepted Answer

A)  The colonies may be due to back mutation (reversion). 
B)  The colonies may be due to recombination. 
C)  Either A or B is possible. 
D)  Neither A nor B is possible. 
A)  The colonies may be due to back mutation (reversion). 
B)  The colonies may be due to recombination. 
C)  Either A or B is possible. 
D)  Neither A nor B is possible.

Question 3

Homologous recombination has been observed in

Accepted Answer

A)  Archaea. 
B)  Bacteria. 
C)  Eukarya. 
D)  All three domains (Archaea, Bacteria, and Eukarya). 
A)  Archaea. 
B)  Bacteria. 
C)  Eukarya. 
D)  All three domains (Archaea, Bacteria, and Eukarya).

Question 4

Consider a mutation in which the change is from UAC to UAU. Both codons specify the amino acid tyrosine. Which type of point mutation is this?

Accepted Answer

A)  silent mutation 
B)  nonsense mutation 
C)  missense mutation 
D)  frameshift mutation 
A)  silent mutation 
B)  nonsense mutation 
C)  missense mutation 
D)  frameshift mutation

Question 5

When the F factor is integrated, all Hfr strains have the origin of replication functioning in the same direction.

Accepted Answer

A) True 
 B)False

Question 6

In specialized transduction, virtually any genetic marker can be transferred from donor to recipient.

Accepted Answer

A) True 
 B)False

Question 7

A deleterious mutation in recA results in

Accepted Answer

A)  a decrease in specific recombination. 
B)  a decrease in homologous recombination. 
C)  an increase in homologous recombination. 
D)  no change in either general or specific recombination. 
A)  a decrease in specific recombination. 
B)  a decrease in homologous recombination. 
C)  an increase in homologous recombination. 
D)  no change in either general or specific recombination.

Question 8

In transformation experiments using a variety of Bacteria, it has been noted that essentially all of the cells in a population can become competent.

Accepted Answer

A) True 
 B)False

Question 9

Horizontal gene transfer in Archaea

Accepted Answer

A)  is infrequent in nature and therefore difficult to use for genetic studies in the laboratory. 
B)  has not been documented, thus all genetic studies of archaea are done via genomic sequencing. 
C)  frequently occurs in nature and has been used to perform genetic studies in the laboratory as well. 
D)  frequently occurs in nature, but there are very few laboratory studies because archaea do not cause human disease. 
A)  is infrequent in nature and therefore difficult to use for genetic studies in the laboratory. 
B)  has not been documented, thus all genetic studies of archaea are done via genomic sequencing. 
C)  frequently occurs in nature and has been used to perform genetic studies in the laboratory as well. 
D)  frequently occurs in nature, but there are very few laboratory studies because archaea do not cause human disease.

Question 10

Genetic recombination involving insertion sequences typically results in what type of mutation?

Accepted Answer

A)  base-pair substitution mutation 
B)  silent mutation 
C)  frameshift mutation 
D)  base-pair deletion mutation 
A)  base-pair substitution mutation 
B)  silent mutation 
C)  frameshift mutation 
D)  base-pair deletion mutation

Question 11

Microinsertions and microdeletions often result in ________ mutations.

Accepted Answer

A)  auxotrophic 
B)  advantageous 
C)  silent 
D)  frameshift 
A)  auxotrophic 
B)  advantageous 
C)  silent 
D)  frameshift

Question 12

Which of the following methods may introduce foreign DNA into a recipient?

Accepted Answer

A)  transformation 
B)  transduction 
C)  conjugation 
D)  transformation, transduction, and conjugation 
A)  transformation 
B)  transduction 
C)  conjugation 
D)  transformation, transduction, and conjugation

Question 13

Following uptake, transforming DNA becomes attached to a competence-specific protein that prevents it from nuclease attack until it reaches the chromosome.

Accepted Answer

A) True 
 B)False

Question 14

The SOS system repairs DNA that has gaps, breaks, and other lesions by

Accepted Answer

A)  cutting DNA from other parts of the genome and pasting it into the gaps or damaged areas. 
B)  stabilizing single-stranded DNA until the next round of normal replication. 
C)  using specialized DNA polymerases that will synthesize a new DNA strand even if there is not a normal complementary DNA strand to act as a template. 
D)  using available mRNA and a special RNA-dependent DNA polymerase to fill in the gaps and replace damaged DNA. 
A)  cutting DNA from other parts of the genome and pasting it into the gaps or damaged areas. 
B)  stabilizing single-stranded DNA until the next round of normal replication. 
C)  using specialized DNA polymerases that will synthesize a new DNA strand even if there is not a normal complementary DNA strand to act as a template. 
D)  using available mRNA and a special RNA-dependent DNA polymerase to fill in the gaps and replace damaged DNA.

Question 15

Most plasmids are circular rather than linear.

Accepted Answer

A) True 
 B)False

Question 16

The process in which related DNA sequences from two different sources are exchanged is called

Accepted Answer

A)  transduction. 
B)  phage conversion. 
C)  reversion. 
D)  homologous recombination. 
A)  transduction. 
B)  phage conversion. 
C)  reversion. 
D)  homologous recombination.

Question 17

Archaea have a unique form of conjugation involving cytoplasmic bridges for bidirectional transfer of DNA.

Accepted Answer

A) True 
 B)False

Question 18

The evolutionary significance of phage conversion likely stems from an effective alteration of host cells.

Accepted Answer

A) True 
 B)False

Question 19

The mutagens 2-aminopurine and 5-bromouracil are examples of

Accepted Answer

A)  alkylating agents. 
B)  nucleotide base analogs. 
C)  chemicals reacting with DNA. 
D)  None of the answers are correct. 
A)  alkylating agents. 
B)  nucleotide base analogs. 
C)  chemicals reacting with DNA. 
D)  None of the answers are correct.

Question 20

The CRISPR system is said to protect or preserve genome integrity in prokaryotic cells by acting as a type of ʺimmune system.ʺ Explain how the CRISPR system works and its limitations.

Accepted Answer

The CRISPR (clustered regularly interspa

Exam 11: Genetics of Bacteria and Archaea

Hfr strains of Escherichia coli

Consider the following experiment. First, large populations of two mutant strains of Escherichia coli are mixed, each requiring a different, single amino acid. After plating them onto a minimal medium, 45 colonies grew. Which of the following may explain this result?

Homologous recombination has been observed in

Consider a mutation in which the change is from UAC to UAU. Both codons specify the amino acid tyrosine. Which type of point mutation is this?

When the F factor is integrated, all Hfr strains have the origin of replication functioning in the same direction.

In specialized transduction, virtually any genetic marker can be transferred from donor to recipient.

A deleterious mutation in recA results in

In transformation experiments using a variety of Bacteria, it has been noted that essentially all of the cells in a population can become competent.

Horizontal gene transfer in Archaea

Genetic recombination involving insertion sequences typically results in what type of mutation?

Microinsertions and microdeletions often result in ________ mutations.

Which of the following methods may introduce foreign DNA into a recipient?

Following uptake, transforming DNA becomes attached to a competence-specific protein that prevents it from nuclease attack until it reaches the chromosome.

The SOS system repairs DNA that has gaps, breaks, and other lesions by

Most plasmids are circular rather than linear.

The process in which related DNA sequences from two different sources are exchanged is called

Archaea have a unique form of conjugation involving cytoplasmic bridges for bidirectional transfer of DNA.

The evolutionary significance of phage conversion likely stems from an effective alteration of host cells.

The mutagens 2-aminopurine and 5-bromouracil are examples of

The CRISPR system is said to protect or preserve genome integrity in prokaryotic cells by acting as a type of ʺimmune system.ʺ Explain how the CRISPR system works and its limitations.

The Microbial World

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Information Flow and Protein Processing

Microbial Growth and Its Control

Microbial Regulatory Systems

Molecular Biology of Microbial Growth

Viruses and Their Replication

Microbial Systems Biology

Viral Genomics, Diversity, and Ecology

Biotechnology and Synthetic Biology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Microorganisms

Diversity of Bacteria

Diversity of Archaea

Diversity of Microbial Eukarya

Taking the Measure of Microbial Systems

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Symbioses with Humans

Microbial Infection and Pathogenesis

Innate Immunity: Broadly Specific Host Defenses

Adaptive Immunity: Highly Specific Host Defenses

Clinical Microbiology and Immunology

Epidemiology

Person-to-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Waterborne and Foodborne Bacterial and Viral Diseases

Eukaryotic Pathogens: Fungi, Protozoans, and Helminths

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