Question 1

A plasmid may

Accepted Answer

A)  replicate independently of the chromosome. 
B)  be transferred cell-to-cell during conjugation. 
C)  be integrated into the chromosome. 
D)  replicate independently of the chromosome, integrate into the chromosome, or be transferred cell-to-cell during conjugation. 
A)  replicate independently of the chromosome. 
B)  be transferred cell-to-cell during conjugation. 
C)  be integrated into the chromosome. 
D)  replicate independently of the chromosome, integrate into the chromosome, or be transferred cell-to-cell during conjugation.

Question 2

Lysogeny probably carries a strong selective advantage for the host cell because it

Accepted Answer

A)  prevents cell lysis. 
B)  confers resistance to infection by viruses of the same type. 
C)  confers resistance to infection by viruses of a different type (or strain). 
D)  confers resistance to infection by many virus types and prevent cell lysis. 
A)  prevents cell lysis. 
B)  confers resistance to infection by viruses of the same type. 
C)  confers resistance to infection by viruses of a different type (or strain). 
D)  confers resistance to infection by many virus types and prevent cell lysis.

Question 3

All Hfr strains integrate into the chromosome at

Accepted Answer

A)  the same locus. 
B)  several specific sites. 
C)  the same locus most of the time, although there may be some variation. 
D)  loci that cannot be accurately determined. 
A)  the same locus. 
B)  several specific sites. 
C)  the same locus most of the time, although there may be some variation. 
D)  loci that cannot be accurately determined.

Question 4

Proteins and nucleic acids absorb light maximally at 260 nm; hence, proteins protect cells from UV effects.

Accepted Answer

A) True 
 B)False

Question 5

Discuss the importance of homologous recombination and transposition in natural horizontal gene transfer and evolution. Be sure to define all of the terms you use and connect them together logically in your answer.

Accepted Answer

Natural horizontal gene transfer is the

Question 6

How does the SOS system simultaneously fix damage DNA and increase the mutation rate? How does the SOS system increase the survival of microorganisms?

Accepted Answer

The SOS system causes the expression of

Question 7

Consider the map shown below of a portion of a prokaryotic genome. How might the elements indicated affect the stability and structure of the genome? Assume that IS2 encodes for a transposase that catalyzes conservative transposition. Re-draw the genome map to illustrate your prediction if necessary.
| IS2 | gene1 gene2 gene3 | IS2 | geneA geneB geneC | IS2 | geneD | IS2 | geneX

Accepted Answer

Answers should indicate that having mult

Question 8

Which of the following is most similar to lysogeny?

Accepted Answer

A)  Hfr state 
B)  F⁺ state 
C)  F⁻ state 
D)  Fʹ state 
A)  Hfr state 
B)  F⁺ state 
C)  F⁻ state 
D)  Fʹ state

Question 9

The CRISPR system

Accepted Answer

A)  facilitates homologous recombination through a complex system of proteins and clustered repeats. 
B)  recognizes foreign DNA sequences that have previously entered the cell and directs the Cas proteins to destroy them. 
C)  repairs DNA and increases DNA damage tolerance during times of stress. 
D)  synthesizes gene transfer agents during stationary phase. 
A)  facilitates homologous recombination through a complex system of proteins and clustered repeats. 
B)  recognizes foreign DNA sequences that have previously entered the cell and directs the Cas proteins to destroy them. 
C)  repairs DNA and increases DNA damage tolerance during times of stress. 
D)  synthesizes gene transfer agents during stationary phase.

Question 10

Transformation and homologous recombination allow for the formation of heteroduplex DNA. Which of the following would occur during DNA replication of this molecule?

Accepted Answer

A)  One daughter strand is complementary to the recombinant DNA molecule, while the other daughter strand is complementary to the parent DNA molecule. 
B)  Both daughter strands are complementary to the recombinant DNA molecule. 
C)  Both daughter strands are complementary to the parent DNA molecule. 
D)  None of the answers are correct. 
A)  One daughter strand is complementary to the recombinant DNA molecule, while the other daughter strand is complementary to the parent DNA molecule. 
B)  Both daughter strands are complementary to the recombinant DNA molecule. 
C)  Both daughter strands are complementary to the parent DNA molecule. 
D)  None of the answers are correct.

Question 11

The F (fertility) plasmid contains a set of genes that encode for the ________ proteins that are essential in conjugative transfer of DNA.

Accepted Answer

A)  pili 
B)  SOS repair 
C)  transduction 
D)  transformation 
A)  pili 
B)  SOS repair 
C)  transduction 
D)  transformation

Question 12

UV radiation is a useful tool in producing mutants of microbial cultures.

Accepted Answer

A) True 
 B)False

Question 13

The designations Phe⁻, Leu⁻, and Ser⁺ refer to an organismʹs

Accepted Answer

A)  plasmid type. 
B)  genotype. 
C)  phenotype. 
D)  mutation type. 
A)  plasmid type. 
B)  genotype. 
C)  phenotype. 
D)  mutation type.

Question 14

In a prokaryotic genome, either insertion elements OR transposons are present, but both are never present at the same time.

Accepted Answer

A) True 
 B)False

Question 15

A typical mutation rate for a bacterium is in the range of 10⁻⁶ to 10⁻⁷ per kbp.

Accepted Answer

A) True 
 B)False

Question 16

How might mutations in the dnaQ sequence, whose enzyme is involved in DNA proofreading, be beneficial for a microbe in a highly competitive and dynamic community?

Accepted Answer

Mutations in dnaQ would result in an inc

Question 17

Consider conjugation in Escherichia coli. In which of the following matings would chromosomal genes be transferred most frequently?

Accepted Answer

A)  F⁺ × F⁻ 
B)  F⁻ × F⁻ 
C)  Hfr × F⁻ 
D)  F⁺ ˣ F⁺ 
A)  F⁺ × F⁻ 
B)  F⁻ × F⁻ 
C)  Hfr × F⁻ 
D)  F⁺ ˣ F⁺

Question 18

Insertion sequences are found on both ends of transposons and encode for transposase.

Accepted Answer

A) True 
 B)False

Question 19

Chemical mutagens, UV radiation, and ionizing radiation all increase mutation rates, but they have different mechanisms. Which type of mutagen would be best suited for creating large deletions and rearrangements within a genome?

Accepted Answer

A)  chemical mutagens 
B)  UV radiation 
C)  ionizing radiation 
D)  Chemical, UV, and ionizing radiation would create large deletions and rearrangements if used in a very high dose. 
A)  chemical mutagens 
B)  UV radiation 
C)  ionizing radiation 
D)  Chemical, UV, and ionizing radiation would create large deletions and rearrangements if used in a very high dose.

Question 20

A phage can be infectious even if all of its DNA has been replaced by bacterial DNA.

Accepted Answer

A) True 
 B)False

Exam 11: Genetics of Bacteria and Archaea

A plasmid may

Lysogeny probably carries a strong selective advantage for the host cell because it

All Hfr strains integrate into the chromosome at

Proteins and nucleic acids absorb light maximally at 260 nm; hence, proteins protect cells from UV effects.

Discuss the importance of homologous recombination and transposition in natural horizontal gene transfer and evolution. Be sure to define all of the terms you use and connect them together logically in your answer.

How does the SOS system simultaneously fix damage DNA and increase the mutation rate? How does the SOS system increase the survival of microorganisms?

Which of the following is most similar to lysogeny?

The CRISPR system

Transformation and homologous recombination allow for the formation of heteroduplex DNA. Which of the following would occur during DNA replication of this molecule?

The F (fertility) plasmid contains a set of genes that encode for the ________ proteins that are essential in conjugative transfer of DNA.

UV radiation is a useful tool in producing mutants of microbial cultures.

The designations Phe⁻, Leu⁻, and Ser⁺ refer to an organismʹs

In a prokaryotic genome, either insertion elements OR transposons are present, but both are never present at the same time.

A typical mutation rate for a bacterium is in the range of 10⁻⁶ to 10⁻⁷ per kbp.

How might mutations in the dnaQ sequence, whose enzyme is involved in DNA proofreading, be beneficial for a microbe in a highly competitive and dynamic community?

Consider conjugation in Escherichia coli. In which of the following matings would chromosomal genes be transferred most frequently?

Insertion sequences are found on both ends of transposons and encode for transposase.

Chemical mutagens, UV radiation, and ionizing radiation all increase mutation rates, but they have different mechanisms. Which type of mutagen would be best suited for creating large deletions and rearrangements within a genome?

A phage can be infectious even if all of its DNA has been replaced by bacterial DNA.

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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