Question 1

All viruses that use a negative-sense RNA genome must package which of the following proteins in their virion?

Accepted Answer

A)  RNA-dependent-RNA-polymerase 
B)  matrix protein 
C)  RNA helicase 
D)  RNA methylase 
E)  scaffolding protein 
A)  RNA-dependent-RNA-polymerase 
B)  matrix protein 
C)  RNA helicase 
D)  RNA methylase 
E)  scaffolding protein A

Question 2

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.

Accepted Answer

A) True 
 B)False  True

Question 3

During a single growth cycle experiment, the titer of extracellular and intracellular virus drops in the first hour.What explains this observation?

Accepted Answer

A)  The virus is inactivated by antibodies in the medium. 
B)  The virus is inactivated by cellular enzymes. 
C)  The virus enters the cell and is uncoated. 
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 
A)  The virus is inactivated by antibodies in the medium. 
B)  The virus is inactivated by cellular enzymes. 
C)  The virus enters the cell and is uncoated. 
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 C

Question 4

The major advantage of a hemagglutination assay to measure the amount of virus particles in a solution is that it is very accurate.

Accepted Answer

A) True 
 B)False

Question 5

The development of which of the following instruments or techniques in the 1930's allowed scientists to visualize viral particles for the first time?

Accepted Answer

A)  polymerase chain reaction 
B)  electron microscope 
C)  confocal microscope 
D)  thermal cycler 
E)  plaque assay 
A)  polymerase chain reaction 
B)  electron microscope 
C)  confocal microscope 
D)  thermal cycler 
E)  plaque assay

Question 6

Which of the following would not be a nucleic acid form found in a viral genome?

Accepted Answer

A)  dsDNA 
B)  ssDNA 
C)  dsRNA 
D)  ssRNA 
E)  an RNA:DNA hybrid 
A)  dsDNA 
B)  ssDNA 
C)  dsRNA 
D)  ssRNA 
E)  an RNA:DNA hybrid

Question 7

The particle to plaque ratio for most animal viruses is much greater than one.What are the reasons why not 100% of animal virus particles, as seen under the electron microscope, can productively infect cells?

Accepted Answer

Not all virus particles as seen under th

Question 8

Which of the following processes in cells was NOT discovered by studying a virus?

Accepted Answer

A)  the sequence of the genetic code. 
B)  DNA replication in both prokaryotic and eukaryotic cells 
C)  DNA is the genetic material 
D)  regulation of gene expression in eukaryotic cells. 
E)  mRNA splicing in eukaryotic cells 
A)  the sequence of the genetic code. 
B)  DNA replication in both prokaryotic and eukaryotic cells 
C)  DNA is the genetic material 
D)  regulation of gene expression in eukaryotic cells. 
E)  mRNA splicing in eukaryotic cells

Question 9

Viruses play a major role in the ecology of the ocean by doing which of the following?

Accepted Answer

A)  By infecting photosynthetic bacteria and increasing their growth. 
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. 
D)  By lysing unicellular organisms and releasing carbon and oxygen back into the ocean. 
E)  All of the above statements are correct. 
A)  By infecting photosynthetic bacteria and increasing their growth. 
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. 
D)  By lysing unicellular organisms and releasing carbon and oxygen back into the ocean. 
E)  All of the above statements are correct.

Question 10

The Baltimore classification system describes the relationship between a viral genome and the:

Accepted Answer

A)  the complementary genome sequence. 
B)  early viral proteins. 
C)  early mRNAs. 
D)  cellular polymerases. 
E)  Latin classification system. 
A)  the complementary genome sequence. 
B)  early viral proteins. 
C)  early mRNAs. 
D)  cellular polymerases. 
E)  Latin classification system.

Question 11

Which of the following is an enzyme that most RNA viruses encode in their genome?

Accepted Answer

A)  DNA-dependent-RNA-polymerase 
B)  RNA-dependent-RNA-polymerase 
C)  DNA-dependent-DNA-polymerase 
D)  RNA-dependent-protein-synthetase 
A)  DNA-dependent-RNA-polymerase 
B)  RNA-dependent-RNA-polymerase 
C)  DNA-dependent-DNA-polymerase 
D)  RNA-dependent-protein-synthetase

Question 12

The word "phage" is a shortened version of the name of a virus that can infect which type of organism?

Accepted Answer

A)  bacterial cell 
B)  human cell 
C)  eukaryotic cell 
D)  plant cell 
E)  inset cell 
A)  bacterial cell 
B)  human cell 
C)  eukaryotic cell 
D)  plant cell 
E)  inset cell

Question 13

Which of the following terms describes the protein shell that surrounds the viral genome?

Accepted Answer

A)  capsid 
B)  envelope 
C)  matrix 
D)  virion 
E)  capsomere 
A)  capsid 
B)  envelope 
C)  matrix 
D)  virion 
E)  capsomere

Question 14

Viruses are not the only obligatory intracellular parasites.Describe how the replication of viruses is different than cellular organisms that replicate inside of cells, like chlamydiae and rickettsiae.

Accepted Answer

Unicellular parasitic cells that need to

Question 15

The study of which group of viruses led to the discovery of cellular genes that can promoter cancer in animal cells?

Accepted Answer

A)  papillomaviruses 
B)  retroviruses 
C)  adneoviruses 
D)  polyomaviruses 
E)  picornaviruses 
A)  papillomaviruses 
B)  retroviruses 
C)  adneoviruses 
D)  polyomaviruses 
E)  picornaviruses

Question 16

Plant viruses use which cellular structures to spread between host cells?

Accepted Answer

A)  endosomes 
B)  plasmodesmata 
C)  plasma membranes 
D)  vesicles 
E)  receptors 
A)  endosomes 
B)  plasmodesmata 
C)  plasma membranes 
D)  vesicles 
E)  receptors

Question 17

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?

Accepted Answer

A)  The genome would be copied into complementary negative RNA. 
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. 
E)  None of the above. 
A)  The genome would be copied into complementary negative RNA. 
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. 
E)  None of the above.

Question 18

Phages, viruses that can infect bacterial cells, may someday be used to treat bacterial infections.

Accepted Answer

A) True 
 B)False

Question 19

Which of the following is a description of a plaque?

Accepted Answer

A)  A viral particle as seen by electron microscopy. 
B)  A region of dead cells in a monolayer of infected cells. 
C)  A skin lesion caused by a virus infection in an animal. 
D)  A button of red blood cells seen in a hemagglutination assay. 
E)  A region of crystallized virus particles in an infected cell. 
A)  A viral particle as seen by electron microscopy. 
B)  A region of dead cells in a monolayer of infected cells. 
C)  A skin lesion caused by a virus infection in an animal. 
D)  A button of red blood cells seen in a hemagglutination assay. 
E)  A region of crystallized virus particles in an infected cell.

Question 20

If you wanted to show that an infectious agent is a virus, what experiment could you do?

Accepted Answer

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. 
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)  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. 
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.

Exam 1: Introduction to Virology

All viruses that use a negative-sense RNA genome must package which of the following proteins in their virion?

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.

During a single growth cycle experiment, the titer of extracellular and intracellular virus drops in the first hour.What explains this observation?

The major advantage of a hemagglutination assay to measure the amount of virus particles in a solution is that it is very accurate.

The development of which of the following instruments or techniques in the 1930's allowed scientists to visualize viral particles for the first time?

Which of the following would not be a nucleic acid form found in a viral genome?

The particle to plaque ratio for most animal viruses is much greater than one.What are the reasons why not 100% of animal virus particles, as seen under the electron microscope, can productively infect cells?

Which of the following processes in cells was NOT discovered by studying a virus?

Viruses play a major role in the ecology of the ocean by doing which of the following?

The Baltimore classification system describes the relationship between a viral genome and the:

Which of the following is an enzyme that most RNA viruses encode in their genome?

The word "phage" is a shortened version of the name of a virus that can infect which type of organism?

Which of the following terms describes the protein shell that surrounds the viral genome?

Viruses are not the only obligatory intracellular parasites.Describe how the replication of viruses is different than cellular organisms that replicate inside of cells, like chlamydiae and rickettsiae.

The study of which group of viruses led to the discovery of cellular genes that can promoter cancer in animal cells?

Plant viruses use which cellular structures to spread between host cells?

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?

Phages, viruses that can infect bacterial cells, may someday be used to treat bacterial infections.

Which of the following is a description of a plaque?

If you wanted to show that an infectious agent is a virus, what experiment could you do?

Virus Structure and Assembly

Virus Classification: The World of Viruses

Virus Entry

Single-Stranded RNA Bacteriophages

Microviruses

Bacteriophage

Bacteriophage Lambda

Viruses of Archaea

Cucumber Mosaic Virus

Picornaviruses

Flaviviruses

Togaviruses

Coronaviruses

Paramyxo-Viruses and Rhabdoviruses

Filovirouses

Bunyaviruses

Influenza Viruses

Reoviruses

Parvoviruses

Polyomaviruses

Papillomaviruses

Adenoviruses

Herpesviruses

Baculoviruses

Poxviruses

Viruses of Algae and Mimivirus

Retroviruses

Human Immunodeficiency

Hepadnaviruses

Viroids and Hepatitis Delta Virus

Prions

Intrinsic Cellular Defenses Against Virus Infection

Innate and Adaptive Immune Responses to Virus Infection

Antiviral Vaccines

Antiviral Chemotherapy

Eukaryotic Virus Vectors

Filters