GMS 6121 Exam 1 Correct questions &
solutions (RATED A)
The 4 things that viruses lack - ANSWER (1) Enzymes that produce basic chemical
building blocks
(2) Enzyme systems that generate usable energy
(3) Enzymes/tRNAs/ribosomes that direct protein synthesis
(4) Membranes that concentrate and localize key molecules
All viruses have _______ and _______, while only some viruses have ________. -
ANSWER nucleic acids and a capsid; an envelope
A ________ is a complete, infectious virus particle. - ANSWER virion
Naked capsids are ______ to drying, heat, detergents, and acid. - ANSWER resistant
Enveloped capsids are ________ to drying, heat, detergents, and acid. - ANSWER
sensitive
General stages of virus infection - ANSWER 1) Adsorption
2) Entry
3) Uncoating
4) Early genes
5) Replication
6) Late genes
7) Assembly
8) Packaging
9) Release
Immunofluorescence - ANSWER method that uses virus-specific antibodies to detect a
specific viral protein, usually in a tissue section biopsy or cells from fluid
ELISA (enzyme-linked immunosorbent assay) - ANSWER method that uses virus-
specific antibodies to detect virus particles or secreted viral proteins in fluid
Electron microscopy - ANSWER method used to detect viral particles in lesions
Cytopathic effects include: - ANSWER -Cell lysis
-Rounding (or other morphological changes)
-Syncytia
-Inclusion bodies
, Virus infection of cultured cells can be observed by cytopathic effect (CPE), which most
frequently manifests as: - ANSWER cell lysis
The most common method to quantify virus infection in a laboratory is by: - ANSWER
plaque assay
Hemaglutination assay can be used to quantify viruses that are able to bind to: -
ANSWER red blood cells
The number of plaques detected in one well of a plaque assay is a reflection of the
amount of ________ and the amount of ________. - ANSWER virus in the sample;
sample dilution
Serology is an indirect method of virus detection because it measures the amount of
_____ in a patient's serum. - ANSWER antibody
Barriers to viral infection of the GI tract - ANSWER -acid pH of the stomach
-bile detergents
-mucosal IgA
-thick layer of mucus
An infection where the virus can spread to many different organs in the body -
ANSWER systemic infection
Viral induction of pyrogenic cytokines that stimulate fever, antibody-dependent
enhancement of viral infection, and generation of immune complexes during chronic
infections are examples of _______. - ANSWER immunopathology
Viruses in nature are _____ genetically diverse than viruses in the laboratory. -
ANSWER more
Reassortment can only occur for which class of virus? - ANSWER Viruses with
segmented genomes
Why do RNA viruses have a higher rate of mutation than DNA viruses? - ANSWER -
Their polymerases lack proof-reading activity
-They have low-fidelity polymerases.
-Their genomes are much smaller so the replication rate is much quicker.
What are the mechanisms by which picornaviruses can release their genomes into the
cytoplasm of target cells? - ANSWER Formation of pores in the membrane AND
dissociation of the virion in acidic endosomes following endocytosis
What factor recruits host translation initiation factors to the 5' end of picornavirus
genomes to initiate protein production? - ANSWER internal ribosome entry site (IRES)
solutions (RATED A)
The 4 things that viruses lack - ANSWER (1) Enzymes that produce basic chemical
building blocks
(2) Enzyme systems that generate usable energy
(3) Enzymes/tRNAs/ribosomes that direct protein synthesis
(4) Membranes that concentrate and localize key molecules
All viruses have _______ and _______, while only some viruses have ________. -
ANSWER nucleic acids and a capsid; an envelope
A ________ is a complete, infectious virus particle. - ANSWER virion
Naked capsids are ______ to drying, heat, detergents, and acid. - ANSWER resistant
Enveloped capsids are ________ to drying, heat, detergents, and acid. - ANSWER
sensitive
General stages of virus infection - ANSWER 1) Adsorption
2) Entry
3) Uncoating
4) Early genes
5) Replication
6) Late genes
7) Assembly
8) Packaging
9) Release
Immunofluorescence - ANSWER method that uses virus-specific antibodies to detect a
specific viral protein, usually in a tissue section biopsy or cells from fluid
ELISA (enzyme-linked immunosorbent assay) - ANSWER method that uses virus-
specific antibodies to detect virus particles or secreted viral proteins in fluid
Electron microscopy - ANSWER method used to detect viral particles in lesions
Cytopathic effects include: - ANSWER -Cell lysis
-Rounding (or other morphological changes)
-Syncytia
-Inclusion bodies
, Virus infection of cultured cells can be observed by cytopathic effect (CPE), which most
frequently manifests as: - ANSWER cell lysis
The most common method to quantify virus infection in a laboratory is by: - ANSWER
plaque assay
Hemaglutination assay can be used to quantify viruses that are able to bind to: -
ANSWER red blood cells
The number of plaques detected in one well of a plaque assay is a reflection of the
amount of ________ and the amount of ________. - ANSWER virus in the sample;
sample dilution
Serology is an indirect method of virus detection because it measures the amount of
_____ in a patient's serum. - ANSWER antibody
Barriers to viral infection of the GI tract - ANSWER -acid pH of the stomach
-bile detergents
-mucosal IgA
-thick layer of mucus
An infection where the virus can spread to many different organs in the body -
ANSWER systemic infection
Viral induction of pyrogenic cytokines that stimulate fever, antibody-dependent
enhancement of viral infection, and generation of immune complexes during chronic
infections are examples of _______. - ANSWER immunopathology
Viruses in nature are _____ genetically diverse than viruses in the laboratory. -
ANSWER more
Reassortment can only occur for which class of virus? - ANSWER Viruses with
segmented genomes
Why do RNA viruses have a higher rate of mutation than DNA viruses? - ANSWER -
Their polymerases lack proof-reading activity
-They have low-fidelity polymerases.
-Their genomes are much smaller so the replication rate is much quicker.
What are the mechanisms by which picornaviruses can release their genomes into the
cytoplasm of target cells? - ANSWER Formation of pores in the membrane AND
dissociation of the virion in acidic endosomes following endocytosis
What factor recruits host translation initiation factors to the 5' end of picornavirus
genomes to initiate protein production? - ANSWER internal ribosome entry site (IRES)
