TEST BANK for Fundamentals of Molecular Virology 2nd b) By infecting harmful bacteria found in the ocean and limiting their growth.
c) By killing off fish and preventing them from becoming too plentiful.
Edition by Acheson. d) By lysing unicellular organisms and releasing carbon and oxygen back into the ocean.
e) All of the above statements are correct.
Package Title: Testbank
Course Title: Acheson 2nd edition Answer: d
Chapter Number: 01
5) If you wanted to show that an infectious agent is a virus, what experiment could you do?
Question type: Multiple Choice a) Show that the agent can be seen under a light microscope.
b) Show that agent contains a lipid membrane.
c) Show that the agent can form single colonies on an agar plate.
1) Which of the following terms describes the protein shell that surrounds the viral genome? d) Show that the agent can be diluted and can still cause disease in an animal.
e) Show that the agent can pass through a porcelain filter and is still infectious.
a) capsid
b) envelope Answer: e
c) matrix
d) virion
e) capsomere 6) What does the word “virus” mean in Latin?
Answer: a a) infectious agent
b) liquid
c) poison
2) Which of the following would not be a nucleic acid form found in a viral genome? d) death
e) disease
a) dsDNA
b) ssDNA Answer: c
c) dsRNA
d) ssRNA
e) an RNA:DNA hybrid 7) The word “phage” is a shortened version of the name of a virus that can infect which type of
organism?
Answer: e
a) bacterial cell
b) human cell
3) Which of the following is an enzyme that most RNA viruses encode in their genome? c) eukaryotic cell
d) plant cell
a) DNA-dependent-RNA-polymerase e) inset cell
b) RNA-dependent-RNA-polymerase
c) DNA-dependent-DNA-polymerase Answer: a
d) DNA-dependent-RNA-polymerase
e) RNA-dependent-protein-synthetase
8) The study of which group of viruses led to the discovery of cellular genes that can promoter cancer in
Answer: b animal cells?
a) papillomaviruses
4) Viruses play a major role in the ecology of the ocean by doing which of the following? b) retroviruses
c) adneoviruses
a) By infecting photosynthetic bacteria and increasing their growth. d) polyomaviruses
,e) picornaviruses c) RNA replicase
d) RNA transcriptase
Answer: b e) Reverse transcriptase
Answer: e
9) When doing a plaque assay with human or animal cells, a layer of nutrient media mixed with agar is 13) Plant viruses use which cellular structures to spread between host cells?
put on top of the cells after they have been infected with the diluted virus. What is the major purpose of
this agar layer? a) endosomes
b) plasmodesmata
a) It helps to feed the cells as they grow. c) plasma membranes
b) It promotes the replication of the virus. d) vesicles
c) It makes the infected cells easier to visualize. e) receptors
d) It limits the movement of virus particles.
e) All of the above are correct. Answer: b
Answer: d
14) All viruses that use a negative-sense RNA genome must package which of the following proteins in
their virion?
10) To start an experiment, you do an infection by putting 0.5 ml of a virus stock that has a titer of 6 x
107 pfu/ml onto a plate of animal cells that contains 5 x 106 cells. What is the multiplicity of infection for a) RNA-dependent-RNA-polymerase
this experiment? b) matrix protein
c) RNA helicase
a) 12 d) RNA methylase
b) 6 e) scaffolding protein
c) 5
d) 3 Answer: a
e) 1
Answer: b 15) Which of the following is a description of a plaque?
a) A viral particle as seen by electron microscopy.
11) During a single growth cycle experiment, the titer of extracellular and intracellular virus drops in the b) A region of dead cells in a monolayer of infected cells.
first hour. What explains this observation? c) A skin lesion caused by a virus infection in an animal.
d) A button of red blood cells seen in a hemagglutination assay.
a) The virus is inactivated by antibodies in the medium. e) A region of crystallized virus particles in an infected cell.
b) The virus is inactivated by cellular enzymes.
c) The virus enters the cell and is uncoated. Answer: b
d) The virus binds to the cells in the dish and can’t be released.
e) The cell’s antiviral defenses prevent replication of the virus
16) Which of the following processes in cells was NOT discovered by studying a virus?
Answer: c
a) the sequence of the genetic code.
b) DNA replication in both prokaryotic and eukaryotic cells
12) What is another term for an RNA-dependent-DNA-polymerase? c) DNA is the genetic material
d) regulation of gene expression in eukaryotic cells.
a) DNA polymerase e) mRNA splicing in eukaryotic cells
b) RNA polymerase II
,Answer: a Answer: e
21) Most DNA viruses that replicate in the nucleus of the host cell use which of the following to
transcribe their genes into mRNA?
17) You are given a solution of virus and asked to determine the titer. You carry out a plaque assay with
0.5mls of a 105 dilution of the virus solution and obtain an average of 150 plaques. What is the titer of a) cellular DNA-dependent-RNA polymerase
the solution? b) viral DNA-dependent-RNA polymerase
c) viral DNA-dependent-DNA polymerase
a) 1.5 x 105 pfu/ml d) cellular DNA-dependent-DNA polymerase
b) 3 x 105 pfu/ml e) viral RNA-dependent-DNA polymerase
c) 1.5 x 107 pfu/ml
d) 3 x 107 pfu/ml Answer: a
e) 1.5 x 108 pfu/ml
Answer: d 22) The development of which of the following instruments or techniques in the 1930’s allowed
scientists to visualize viral particles for the first time?
18) The Baltimore classification system describes the relationship between a viral genome and the: a) polymerase chain reaction
b) electron microscope
a) the complementary genome sequence. c) confocal microscope
b) early viral proteins. d) thermal cycler
c) early mRNAs. e) plaque assay
d) cellular polymerases.
e) Latin classification system. Answer: b
Answer: c
Question Type: True/False
19) If the genome of a positive-strand RNA virus, which has been purified away from all of the virion
proteins, was injected into the cytoplasm of an appropriate host cell, what would happen first? 24) The common cold can be caused by viruses from three different families, some of which have RNA
genomes and some of which have DNA genomes.
a) The genome would be copied into complementary negative RNA.
b) The genome would be translated by cellular ribosome’s. Answer: True
c) The genome would be transcribed by a cellular RNA-dependent-RNA-polymerase.
d) The genome would be transcribed by a viral RNA-dependent-RNA-polymerase.
e) None of the above. 25) The major advantage of a hemagglutination assay to measure the amount of virus particles in a
solution is that it is very accurate.
Answer: b
Answer: False
20) If the genome of a negative-strand RNA virus, which has been purified away from all of the virion
proteins, was injected into the cytoplasm of an appropriate host cell, what would happen first? 26) Phages, viruses that can infect bacterial cells, may someday be used to treat bacterial infections.
a) The genome would be copied into complementary negative RNA. Answer: True
b) The genome would be translated by cellular ribosome’s.
c) The genome would be transcribed by a cellular RNA-dependent-RNA-polymerase.
d) The genome would be transcribed by a viral RNA-dependent-RNA-polymerase. Question type: Essay
e) None of the above.
, 27) The particle to plaque ratio for most animal viruses is much greater than one. What are the reasons e) icosahedral capsid and an envelope
why not 100% of animal virus particles, as seen under the electron microscope, can productively infect
cells? Answer: a
Answer: Not all virus particles as seen under the electron microscope are intact virions capable of
binding and entering a host cell. Some virus particles contain defective genomes that lack one or more 3) Depending on the type of virus, which of the following is a function of the virus capsid?
critical genes necessary for viral replication. Some viral particles contain empty capsids, which means
that there is not genome inside the virion. Finally, cells have many antiviral defense mechanisms that a) To attach to the correct type of host cell.
can shut down a virus infection before it can be completed. b) To protect the viral genome from nucleases.
c) To ensure delivery of the genome into the host cell.
d) To protect the viral genome from damage by UV light.
28) Viruses are not the only obligatory intracellular parasites. Describe how the replication of viruses is e) All of the above functions are correct.
different than cellular organisms that replicate inside of cells, like chlamydiae and rickettsiae.
Answer: e
Answer: Unicellular parasitic cells that need to replicate inside of other cells do not replicate in the same
way that viruses do. First of all, unicellular parasites have their own ribosomes to translate their mRNAs
and do not use the host cell ribosomes, like viruses do. In addition they are intact cells that contain their 4) Virus particles can be visualized with which of the following?
genome entirely within their own cellular membranes and do not release their genome into the host
cell, the way that viruses do. These cellular parasites undergo binary fission in the same way that a) negative staining of virions with electron microscopy
independently living cells do. Viruses do not have their own ribosomes and actually disintegrate their b) negative staining of virions with x-ray diffraction
virion, releasing the genome out of the capsid and into the cytoplasm before they begin their c) negative staining of thin sections of infected cells with electron microscopy
replication. They do not undergo binary fission. d) positive staining in cryoelectron microscopy
e) positive staining of infected cells with x-ray diffraction
Package Title: Testbank
Course Title: Acheson 2nd edition Answer: a
Chapter Number: 02
5) Most viruses that use a spherical shaped capsid arrange their capsid proteins with which of the
following symmetries?
Question type: Multiple Choice
a) cubic
b) tetrahedral
1) The lipid membrane that surrounds the nucleocapsid of some virus particles is called the: c) icosahedral
d) dodecagon
a) matrix e) helical
b) tegument
c) capsid Answer: c
d) envelope
e) glycoprotein
6) Which of the following is NOT a characteristic of a regular icosahedron?
Answer: d
a) It has 12 vertices of 5-fold symmetry.
b) It has 20 triangular faces.
2) The nucleocapsid describes the structure that includes the: c) It has 20 sides with 3-fold symmetry.
d) It has 30 edges with 2-fold symmetry
a) capsid and the genome e) It has 6 square faces.
b) capsid and the envelope
c) envelope and the glycoproteins Answer: e
d) helical capsid and an envelope
c) By killing off fish and preventing them from becoming too plentiful.
Edition by Acheson. d) By lysing unicellular organisms and releasing carbon and oxygen back into the ocean.
e) All of the above statements are correct.
Package Title: Testbank
Course Title: Acheson 2nd edition Answer: d
Chapter Number: 01
5) If you wanted to show that an infectious agent is a virus, what experiment could you do?
Question type: Multiple Choice a) Show that the agent can be seen under a light microscope.
b) Show that agent contains a lipid membrane.
c) Show that the agent can form single colonies on an agar plate.
1) Which of the following terms describes the protein shell that surrounds the viral genome? d) Show that the agent can be diluted and can still cause disease in an animal.
e) Show that the agent can pass through a porcelain filter and is still infectious.
a) capsid
b) envelope Answer: e
c) matrix
d) virion
e) capsomere 6) What does the word “virus” mean in Latin?
Answer: a a) infectious agent
b) liquid
c) poison
2) Which of the following would not be a nucleic acid form found in a viral genome? d) death
e) disease
a) dsDNA
b) ssDNA Answer: c
c) dsRNA
d) ssRNA
e) an RNA:DNA hybrid 7) The word “phage” is a shortened version of the name of a virus that can infect which type of
organism?
Answer: e
a) bacterial cell
b) human cell
3) Which of the following is an enzyme that most RNA viruses encode in their genome? c) eukaryotic cell
d) plant cell
a) DNA-dependent-RNA-polymerase e) inset cell
b) RNA-dependent-RNA-polymerase
c) DNA-dependent-DNA-polymerase Answer: a
d) DNA-dependent-RNA-polymerase
e) RNA-dependent-protein-synthetase
8) The study of which group of viruses led to the discovery of cellular genes that can promoter cancer in
Answer: b animal cells?
a) papillomaviruses
4) Viruses play a major role in the ecology of the ocean by doing which of the following? b) retroviruses
c) adneoviruses
a) By infecting photosynthetic bacteria and increasing their growth. d) polyomaviruses
,e) picornaviruses c) RNA replicase
d) RNA transcriptase
Answer: b e) Reverse transcriptase
Answer: e
9) When doing a plaque assay with human or animal cells, a layer of nutrient media mixed with agar is 13) Plant viruses use which cellular structures to spread between host cells?
put on top of the cells after they have been infected with the diluted virus. What is the major purpose of
this agar layer? a) endosomes
b) plasmodesmata
a) It helps to feed the cells as they grow. c) plasma membranes
b) It promotes the replication of the virus. d) vesicles
c) It makes the infected cells easier to visualize. e) receptors
d) It limits the movement of virus particles.
e) All of the above are correct. Answer: b
Answer: d
14) All viruses that use a negative-sense RNA genome must package which of the following proteins in
their virion?
10) To start an experiment, you do an infection by putting 0.5 ml of a virus stock that has a titer of 6 x
107 pfu/ml onto a plate of animal cells that contains 5 x 106 cells. What is the multiplicity of infection for a) RNA-dependent-RNA-polymerase
this experiment? b) matrix protein
c) RNA helicase
a) 12 d) RNA methylase
b) 6 e) scaffolding protein
c) 5
d) 3 Answer: a
e) 1
Answer: b 15) Which of the following is a description of a plaque?
a) A viral particle as seen by electron microscopy.
11) During a single growth cycle experiment, the titer of extracellular and intracellular virus drops in the b) A region of dead cells in a monolayer of infected cells.
first hour. What explains this observation? c) A skin lesion caused by a virus infection in an animal.
d) A button of red blood cells seen in a hemagglutination assay.
a) The virus is inactivated by antibodies in the medium. e) A region of crystallized virus particles in an infected cell.
b) The virus is inactivated by cellular enzymes.
c) The virus enters the cell and is uncoated. Answer: b
d) The virus binds to the cells in the dish and can’t be released.
e) The cell’s antiviral defenses prevent replication of the virus
16) Which of the following processes in cells was NOT discovered by studying a virus?
Answer: c
a) the sequence of the genetic code.
b) DNA replication in both prokaryotic and eukaryotic cells
12) What is another term for an RNA-dependent-DNA-polymerase? c) DNA is the genetic material
d) regulation of gene expression in eukaryotic cells.
a) DNA polymerase e) mRNA splicing in eukaryotic cells
b) RNA polymerase II
,Answer: a Answer: e
21) Most DNA viruses that replicate in the nucleus of the host cell use which of the following to
transcribe their genes into mRNA?
17) You are given a solution of virus and asked to determine the titer. You carry out a plaque assay with
0.5mls of a 105 dilution of the virus solution and obtain an average of 150 plaques. What is the titer of a) cellular DNA-dependent-RNA polymerase
the solution? b) viral DNA-dependent-RNA polymerase
c) viral DNA-dependent-DNA polymerase
a) 1.5 x 105 pfu/ml d) cellular DNA-dependent-DNA polymerase
b) 3 x 105 pfu/ml e) viral RNA-dependent-DNA polymerase
c) 1.5 x 107 pfu/ml
d) 3 x 107 pfu/ml Answer: a
e) 1.5 x 108 pfu/ml
Answer: d 22) The development of which of the following instruments or techniques in the 1930’s allowed
scientists to visualize viral particles for the first time?
18) The Baltimore classification system describes the relationship between a viral genome and the: a) polymerase chain reaction
b) electron microscope
a) the complementary genome sequence. c) confocal microscope
b) early viral proteins. d) thermal cycler
c) early mRNAs. e) plaque assay
d) cellular polymerases.
e) Latin classification system. Answer: b
Answer: c
Question Type: True/False
19) If the genome of a positive-strand RNA virus, which has been purified away from all of the virion
proteins, was injected into the cytoplasm of an appropriate host cell, what would happen first? 24) The common cold can be caused by viruses from three different families, some of which have RNA
genomes and some of which have DNA genomes.
a) The genome would be copied into complementary negative RNA.
b) The genome would be translated by cellular ribosome’s. Answer: True
c) The genome would be transcribed by a cellular RNA-dependent-RNA-polymerase.
d) The genome would be transcribed by a viral RNA-dependent-RNA-polymerase.
e) None of the above. 25) The major advantage of a hemagglutination assay to measure the amount of virus particles in a
solution is that it is very accurate.
Answer: b
Answer: False
20) If the genome of a negative-strand RNA virus, which has been purified away from all of the virion
proteins, was injected into the cytoplasm of an appropriate host cell, what would happen first? 26) Phages, viruses that can infect bacterial cells, may someday be used to treat bacterial infections.
a) The genome would be copied into complementary negative RNA. Answer: True
b) The genome would be translated by cellular ribosome’s.
c) The genome would be transcribed by a cellular RNA-dependent-RNA-polymerase.
d) The genome would be transcribed by a viral RNA-dependent-RNA-polymerase. Question type: Essay
e) None of the above.
, 27) The particle to plaque ratio for most animal viruses is much greater than one. What are the reasons e) icosahedral capsid and an envelope
why not 100% of animal virus particles, as seen under the electron microscope, can productively infect
cells? Answer: a
Answer: Not all virus particles as seen under the electron microscope are intact virions capable of
binding and entering a host cell. Some virus particles contain defective genomes that lack one or more 3) Depending on the type of virus, which of the following is a function of the virus capsid?
critical genes necessary for viral replication. Some viral particles contain empty capsids, which means
that there is not genome inside the virion. Finally, cells have many antiviral defense mechanisms that a) To attach to the correct type of host cell.
can shut down a virus infection before it can be completed. b) To protect the viral genome from nucleases.
c) To ensure delivery of the genome into the host cell.
d) To protect the viral genome from damage by UV light.
28) Viruses are not the only obligatory intracellular parasites. Describe how the replication of viruses is e) All of the above functions are correct.
different than cellular organisms that replicate inside of cells, like chlamydiae and rickettsiae.
Answer: e
Answer: Unicellular parasitic cells that need to replicate inside of other cells do not replicate in the same
way that viruses do. First of all, unicellular parasites have their own ribosomes to translate their mRNAs
and do not use the host cell ribosomes, like viruses do. In addition they are intact cells that contain their 4) Virus particles can be visualized with which of the following?
genome entirely within their own cellular membranes and do not release their genome into the host
cell, the way that viruses do. These cellular parasites undergo binary fission in the same way that a) negative staining of virions with electron microscopy
independently living cells do. Viruses do not have their own ribosomes and actually disintegrate their b) negative staining of virions with x-ray diffraction
virion, releasing the genome out of the capsid and into the cytoplasm before they begin their c) negative staining of thin sections of infected cells with electron microscopy
replication. They do not undergo binary fission. d) positive staining in cryoelectron microscopy
e) positive staining of infected cells with x-ray diffraction
Package Title: Testbank
Course Title: Acheson 2nd edition Answer: a
Chapter Number: 02
5) Most viruses that use a spherical shaped capsid arrange their capsid proteins with which of the
following symmetries?
Question type: Multiple Choice
a) cubic
b) tetrahedral
1) The lipid membrane that surrounds the nucleocapsid of some virus particles is called the: c) icosahedral
d) dodecagon
a) matrix e) helical
b) tegument
c) capsid Answer: c
d) envelope
e) glycoprotein
6) Which of the following is NOT a characteristic of a regular icosahedron?
Answer: d
a) It has 12 vertices of 5-fold symmetry.
b) It has 20 triangular faces.
2) The nucleocapsid describes the structure that includes the: c) It has 20 sides with 3-fold symmetry.
d) It has 30 edges with 2-fold symmetry
a) capsid and the genome e) It has 6 square faces.
b) capsid and the envelope
c) envelope and the glycoproteins Answer: e
d) helical capsid and an envelope
