Question 1

Intercalating agents,like acridine orange and ethidium bromide,lead to mutagenesis by pushing DNA base pairs apart,which can lead to insertions or deletions.

Accepted Answer

A) True 
 B)False

Question 2

Ionizing radiation does NOT include

Accepted Answer

A) gamma rays. 
B) UV rays. 
C) X-rays. 
D) cosmic rays. 
A) gamma rays. 
B) UV rays. 
C) X-rays. 
D) cosmic rays.

Question 3

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 4

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 5

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 6

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 7

F⁻ strains of Escherichia coli

Accepted Answer

A) do not have an F factor. 
B) have the F factor as a plasmid. 
C) have an integrated F factor. 
D) transfer the F factor to other strains at a high frequency. 
A) do not have an F factor. 
B) have the F factor as a plasmid. 
C) have an integrated F factor. 
D) transfer the F factor to other strains at a high frequency.

Question 8

Integration of linear transforming DNA into the chromosome

Accepted Answer

A) is not required for the expression for the transformed genes. 
B) is catalyzed by the RecA gene. 
C) almost never occurs because restriction endonuclease will degrade the DNA before it is integrated. 
D) only occurs in laboratory-based systems in artificial competent cells. 
A) is not required for the expression for the transformed genes. 
B) is catalyzed by the RecA gene. 
C) almost never occurs because restriction endonuclease will degrade the DNA before it is integrated. 
D) only occurs in laboratory-based systems in artificial competent cells.

Question 9

Laboratory-based genetic systems have been difficult to develop for Archaea,because they do NOT naturally undergo conjugation or transduction.

Accepted Answer

A) True 
 B)False

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

Mutation rates are similar in Bacteria and Archaea,yet certain stressful conditions mutation rates increase.Why is the mutation rate not constant and close to zero all of the time?

Accepted Answer

A) Increased mutation rates can be advantageous in rapidly changing environments because some random mutations may be useful for survival. 
B) Microorganisms carefully control the mutation rate of their DNA to match the environmental conditions and maximize evolution. 
C) The increased mutation rate under stressful conditions is an indication that the microorganisms can no longer replicate their DNA properly and are about to die. 
D) Constant mutation rates would halt evolution completely. 
A) Increased mutation rates can be advantageous in rapidly changing environments because some random mutations may be useful for survival. 
B) Microorganisms carefully control the mutation rate of their DNA to match the environmental conditions and maximize evolution. 
C) The increased mutation rate under stressful conditions is an indication that the microorganisms can no longer replicate their DNA properly and are about to die. 
D) Constant mutation rates would halt evolution completely.

Question 12

Which of the following factors has delayed the development of laboratory-based genetic systems in Archaea?

Accepted Answer

A) There are no documented systems of conjugation in Archaea. 
B) Homologous recombination does NOT occur in Archaea. 
C) Archaea do NOT host viruses or plasmids. 
D) Many archaea grow in extreme or unusual conditions that make the use of agar and traditional mutant screening techniques problematic. 
A) There are no documented systems of conjugation in Archaea. 
B) Homologous recombination does NOT occur in Archaea. 
C) Archaea do NOT host viruses or plasmids. 
D) Many archaea grow in extreme or unusual conditions that make the use of agar and traditional mutant screening techniques problematic.

Question 13

The uptake of DNA released from a cell is ________,while transfer of DNA with cell-to-cell contact would most likely result in ________.

Accepted Answer

A) transformation / conjugation 
B) transduction / conjugation 
C) conjugation / transformation 
D) transformation / transduction 
A) transformation / conjugation 
B) transduction / conjugation 
C) conjugation / transformation 
D) transformation / transduction

Question 14

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 15

Which of the following proteins is NOT required for homologous recombination?

Accepted Answer

A) Hfr 
B) RecA 
C) proteins having helicase activity 
D) endonuclease 
A) Hfr 
B) RecA 
C) proteins having helicase activity 
D) endonuclease

Question 16

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 17

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 18

Transposition is a(n)

Accepted Answer

A) homologous recombination event. 
B) analogous recombination event. 
C) site-specific recombination event. 
D) general recombination event. 
A) homologous recombination event. 
B) analogous recombination event. 
C) site-specific recombination event. 
D) general recombination event.

Question 19

The killing of cells by UV irradiation involves

Accepted Answer

A) absorption at 260 nm by proteins only. 
B) absorption at 260 nm by RNA only. 
C) formation of pyrimidine dimers. 
D) formation of purine dimers. 
A) absorption at 260 nm by proteins only. 
B) absorption at 260 nm by RNA only. 
C) formation of pyrimidine dimers. 
D) formation of purine dimers.

Question 20

Penicillin selection is a positive selection for the isolation of mutants with growth factor requirements.

Accepted Answer

A) True 
 B)False

Exam 10: Genetics of Bacteria and Archaea

Intercalating agents,like acridine orange and ethidium bromide,lead to mutagenesis by pushing DNA base pairs apart,which can lead to insertions or deletions.

Ionizing radiation does NOT include

A deleterious mutation in recA results in

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

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

F⁻ strains of Escherichia coli

Integration of linear transforming DNA into the chromosome

Laboratory-based genetic systems have been difficult to develop for Archaea,because they do NOT naturally undergo conjugation or transduction.

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

Mutation rates are similar in Bacteria and Archaea,yet certain stressful conditions mutation rates increase.Why is the mutation rate not constant and close to zero all of the time?

Which of the following factors has delayed the development of laboratory-based genetic systems in Archaea?

The uptake of DNA released from a cell is ________,while transfer of DNA with cell-to-cell contact would most likely result in ________.

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

Which of the following proteins is NOT required for homologous recombination?

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?

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.

Transposition is a(n)

The killing of cells by UV irradiation involves

Penicillin selection is a positive selection for the isolation of mutants with growth factor requirements.

Microorganisms and Microbiology

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Biology

Microbial Growth and Control

Microbial Genomics

Metabolic Regulation

Viruses and Virology

Viral Genomes and Diversity

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters

The uptake of DNA released from a cell is ,while transfer of DNA with cell-to-cell contact would most likely result in .