How do all viruses differ from bacteria?
-Viruses are not
composed of cells.
-Viruses are filterable.
-Viruses are obligate intracellular parasites.
-Viruses do not have any nucleic acid.
-Viruses do not reproduce.
-Viruses are not composed of cells.
A feature that may be found in viruses but never in bacteria
is
-an ability to infect more than one type of host.
-they
cannot reproduce themselves outside a host.
-the ability to pass
through 0.22 micrometer pore filters.
-may contain an RNA genome.
-a sensitivity to antibiotics
-may contain an RNA genome
Which of the following statements about viral spikes is FALSE?
-They may cause hemagglutination.
-They bind to receptors on the host cell surface.
-They are found only on nonenveloped viruses.
-They are used for attachment.
-They are composed of carbohydrate-protein complexes
-They are found only on nonenveloped viruses.
Which of the following is NOT used as a criterion to classify
viruses?
-biochemical tests
-size
-morphology
-nucleic acid
-number of capsomeres
- biochemical tests
Which of the following is NOT utilized to culture
viruses?
-embryonated eggs
-animal cell cultures
-laboratory animals
-culture media
-bacterial cultures
-culture media
Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps
-release
-uncoating
-penetration
-attachment
-biosynthesis
-biosynthesis
The definition of lysogeny is
-when the burst time takes an
unusually long time.
-attachment of a phage to a cell.
-phage DNA is incorporated into host cell DNA.
-lysis of the host cell due to a phage.
-the period during replication when virions are not present.
-phage DNA is incorporated into host cell DNA.
A viroid is a(n)
-infectious protein.
-provirus.
-capsid without nucleic acid.
-complete, infectious virus particle.
-infectious piece of RNA without a capsid.
- infectious piece of RNA without a capsid.
In Figure 13.1, which structure is a complex virus?
-a
-b
-c
-d
-All of the structures are complex viruses.
- b
The morphological types of viruses illustrated in Figure 13.1 are ultimately determined by the
-membrane spikes.
-capsomeres.
-viroids.
-envelope.
-nucleic acid.
- nucleic acid
A clear area against a confluent "lawn" of bacteria is
called a
-rash.
-cell lysis.
-plaque.
-pock.
-phage.
- plaque
Continuous cell lines differ from primary cell lines in
that
-continuous cell lines always have to be re-isolated from
animal tissues.
-viruses can be grown in continuous cell lines.
-continuous cell lines can be maintained through an indefinite number of generations.
-continuous cell lines are from human embryos.
-continuous cell lines are derived from primary cell lines.
- continuous cell lines can be maintained through an indefinite number of generations.
Which of the following is necessary for replication of a
prion?
- lysozyme
-DNA polymerase
-DNA
-PrPSc
-RNA
- PrPSc
A persistent infection is one in which
-host cells are transformed.
-host cells are gradually lysed.
-the virus remains in equilibrium with the host without causing a disease.
-the disease process occurs gradually over a long period.
-viral replication is unusually slow.
- the disease process occurs gradually over a long period.
An example of a persistent viral infection is
-Varicellavirus infection.
-Influenza.
-Herpes Simplex Virus infection.
-Hepatitis A infection.
-Human Immunodeficiency Virus infection
- Varicellavirus infection.
Lysogeny can result in all of the following EXCEPT
-immunity to
reinfection by the same phage.
-immunity to reinfection by any phage.
-acquisition of new characteristics by the host cell.
-specialized transduction.
-phage conversion.
- immunity to reinfection by any phage.
Which of the following would be the first step in biosynthesis of a
virus with a - (minus) strand of RNA?
-synthesis of
double-stranded RNA from a DNA template
-transcription of mRNA from DNA
-synthesis of double-stranded RNA from an RNA template
-synthesis of DNA from an RNA template
-synthesis of DNA from a DNA template
- synthesis of double-stranded RNA from an RNA template
An infectious protein is a
-retrovirus.
-viroid.
-papovavirus.
-prion.
-bacteriophage.
- prion
An envelope is acquired during which of the following steps?
-biosynthesis
-release
-adsorption
-penetration
-uncoating
- release
Which of the following statements is NOT true of
lysogeny?
-Lytic cycle may follow lysogeny.
-Prophage is inserted into the host genome.
-It causes lysis of host cells.
-It can give infected pathogens the genetic information for toxin production.
-It is a "silent" infection; the virus does not replicate.
- It causes lysis of host cells.
An example of a latent viral infection is
-subacute sclerosing panencephalitis.
-cold sores.
-smallpox.
-influenza.
-mumps.
- cold sores
A virus's ability to infect an animal cell depends primarily upon
the
-host cell's ability to phagocytize viral particles.
-enzymatic activity of a host cell.
-type of viral nucleic acid.
-presence of receptor sites on the cell membrane.
-presence of pili on the host cell wall.
- presence of receptor sites on the cell membrane.
Assume you have isolated an unknown virus. This virus has a single,
positive sense strand of RNA, and possesses an envelope. To which
group does it most likely belong?
-herpesvirus
-retrovirus
-togavirus
-picornavirus
-papovavirus
- togavirus
The mechanism whereby an enveloped virus leaves a host cell is
called
-abduction.
- penetration.
-lysogeny.
-transduction.
-budding.
-budding
The most conclusive evidence that viruses cause cancers was provided
by
-the presence of antibodies against viruses in cancer patients.
-finding oncogenes in viruses.
-cancer that developed in chickens following injection of cell-free filtrates.
-treating cancer with antibodies.
-some liver cancer patients having had hepatitis.
- cancer that developed in chickens following injection of cell-free filtrates.
Bacteriophages derive all of the following from the host cell EXCEPT
-ATP.
-amino acids.
-nucleotides.
-lysozyme.
-tRNA.
- lysozyme
Bacteriophage replication differs from animal virus replication
because only bacteriophage replication involves
-replication of
viral nucleic acid.
-injection of naked nucleic acid into the host cell.
-assembly of viral components.
-lysis of the host cell.
-adsorption to specific receptors.
- injection of naked nucleic acid into the host cell.
Generally, in an infection caused by a DNA-containing virus, the host
animal cell supplies all of the following EXCEPT
- tRNA.
-RNA polymerase.
-nucleotides.
-DNA polymerase.
-None of the answers are correct; all of these are supplied by the host animal cell.
- DNA polymerase.
Which of the following places these items in the correct order for
DNA-virus replication?
1. Maturation
2. DNA
synthesis
3. Transcription
4. Translation
- 1; 2; 3; 4
- 3; 4; 1; 2
- 4; 1; 2; 3
-2; 3; 4; 1
-4; 3; 2; 1
- 2; 3; 4; 1
A viral species is a group of viruses that
-has the same genetic
information and ecological niche.
-infects the same cells and cause the same disease.
-has the same morphology and nucleic acid.
-cannot be defined.
- has the same genetic information and ecological niche.
Viruses that utilize reverse transcriptase belong to the virus families
-Retroviridae and Picornaviridae.
-Hepadnaviridae and Retroviridae.
-Rhabdoviridae and Herpesviridae.
-Herpesviridae and Retroviridae.
-Herpesviridae and Poxviridae.
- Hepadnaviridae and Retroviridae.
DNA made from an RNA template will be incorporated into the virus
capsid of
- influenzavirus.
-Retroviridae.
-Hepadnaviridae.
-Herpesviridae.
-bacteriophage families.
- Hepadnaviridae.
Which of the following statements about viruses is
FALSE?
-Viruses use their own catabolic enzymes.
-Viruses use the anabolic machinery of the cell.
-Viruses contain a protein coat.
-Viruses contain DNA or RNA but never both.
-Viruses have genes.
- Viruses use their own catabolic enzymes.
A lytic virus has infected a patient. Which of the following would
best describe what is happening inside the patient?
-The virus is
infecting cells and then releasing only small amounts of virus.
-The virus is incorporating its nucleic acid with that of the patient's cells.
-The virus is slowly killing the patient's cells.Correct!
-The virus is causing the death of the infected cells in the patient.
-The virus is not killing any cells in the host.
- The virus is causing the death of the infected cells in the patient.