Chapter 7 objectives Flashcards
Reverse transcriptase synthesizes:
viral DNA from RNA.
a positive RNA strand from a negative RNA strand.
viral RNA from DNA.
a negative RNA strand from a positive RNA strand.
viral DNA from RNA.
Viruses acquire envelopes around their nucleocapsids during:
replication.
release.
penetration.
adsorption.
release.
Infectious naked strands of RNA that affect plants are called
spikes.
viroids.
phages.
prions.
viroids.
Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes
patches.
pocks.
buds.
plaques.
pocks.
Tamiflu is a common medication given for influenza treatment, its action being to protect and block sialic acid molecules on the surfaces of host cells and influenza virus envelopes as they leave the cell. Which statement reflects the mechanism of Tamiflu’s action?
Tamiflu interferes with the replication of +ssRNA from the -ssRNA genome of the flu virus.
Tamiflu interferes with the release of the budding viruses from the infected host cells.
Tamiflu blocks protein synthesis of the viral genome.
Tamiflu interferes with the metabolic properties of the virus.
Tamiflu interferes with the release of the budding viruses from the infected host cells.
Which of the following represents a virus family name?
Herpes simplex virus
Picornavirus
Herpesviridae
Enterovirus
Hepatitis B virus
Herpesviridae
Infectious protein particles are called
viroids.
spikes.
phages.
prions.
prions.
Freshly isolated animal tissue that is placed in a growth medium and allowed to produce a cell monolayer is referred to as a/n _____.
secondary
initial
primary
positive
continuous
primary
Select the statement that most accurately describes the action of antimicrobial drugs today.
Antiviral drugs often result in toxic side effects due to their inhibition of host cell activity.
The development of antiviral drug resistance has not been observed, as compared to the high rate of antibiotic resistance seen today.
Antiviral drug treatment is more effective than vaccination against a viral disease.
Effective antiviral drugs have a long history of development and use.
Antiviral drugs often result in toxic side effects due to their inhibition of host cell activity.
Which of the following is correct about prophages?
present when the virus is in lysogeny
formed when viral DNA enters the bacterial chromosome
cause lysis of host cells
occur when temperate phages enter host cells
Present when the virus is in lysogeny
Formed when viral DNA enters the bacterial chromosome
Occur when temperate phases enter host cells
During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the host
cytoplasm.
nucleus.
DNA.
cell membrane.
DNA
Viral tissue specificities are called
ranges.
tropisms.
virions.
receptacles.
tropisms.
Creutzfeldt-Jacob disease is
also called “mad cow disease.”
caused by a chronic latent virus.
a spongiform encephalopathy of humans.
initiated by an oncogenic virus.
a spongiform encephalopathy of humans.
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is:
host cell synthesis of viral enzymes and capsid proteins.
injection of only the viral nucleic acid into the host cell.
assembly of nucleocapsids.
adsorption to the host cells.
injection of only the viral nucleic acid into the host cell.
New, nonenveloped virus release occurs by
exocytosis.
lysis.
both lysis and budding.
budding.
lysis.
Viral capsids are made from subunits called:
spikes.
peptones.
capsomeres.
envelopes.
capsomeres.
Some animals can become infected with multiple influenza virus strains usually associated with other animals. Which statement below describes the result of these infections?
All are possible outcomes.
The viral genomes within the host cells can become recombined.
Major genetic variations in the flu viruses can be reproduced.
A new novel strain of flu may be produced, for which the human population has no immunity.
All are possible outcomes.
One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a/n _____ capsid.
icosahedral
complex
helical
spiked
icosahedral
A common method for cultivating viruses in the lab is to use in vitro systems called _____ cultures.
cell
egg
plaque
embryo
bacteriophage
cell
Viral nucleic acid types include:
Group of answer choices
single-stranded RNA
single-stranded DNA
All of the choices are correct.
double-stranded RNA
double-stranded DNA
All of the choices are correct.
When a bacterium acquires a trait from its temperate phage, it is called
Group of answer choices
transformation.
viral persistence.
lysogenic conversion.
translation.
transcription.
lysogenic conversion.
Viral spikes
Group of answer choices
are derived from host proteins.
are always present on enveloped viruses.
attach the viral capsid and envelope.
allow bacteria to evade host defenses.
are for recognition among the various types of viruses.
are always present on enveloped viruses.
Which of the following will not support viral cultivation?
Group of answer choices
continuous cell cultures
embryonated bird eggs
live lab animals
All of the choices will support viral cultivation.
primary cell cultures
All of the choices will support viral cultivation.
The envelope of enveloped viruses
Group of answer choices
is obtained by viral budding or exocytosis.
is identical to the host plasma membrane.
always includes spikes.
makes the virus very susceptible to drug therapy.
is only composed of host endomembrane.
is obtained by viral budding or exocytosis.
Satellite viruses are
Group of answer choices
also called viroids.
dependent on other viruses for replication.
the cause of spongiform encephalopathies.
significant pathogens of plants.
dependent on other viruses for replication.
Viruses
Group of answer choices
undergo binary fission.
cannot be seen in a light microscope.
are prokaryotic.
contain 70S ribosomes.
cannot be seen in a light microscope.
