Studied by 173 PeopleWhich organisms can be infected by viruses?
Tags & Description
Which organisms can be infected by viruses?
All of them
True or False: Viruses are small enough to pass through a 0.2 micron filter
True
Do all viruses have envelopes?
No
What was a major advancement in virology that allowed us to examine the lifecycle of viruses?
Development of viral tissue culture
How far back in time did viruses originate
4 billion years ago
Viruses that are enveloped obtain this structure from which part or parts of the host cell?
Plasma Membrane
What proteinaceous structure connects the capsid to the envelope
Matrix
Highest to lowest order of the rank system
Realm, Order, Family, Genus, Species
Baltimore Classification System is based off of what viral component
Viral nucleic acid within the virion
What enzyme must all RNA viruses bring into the infected cell with them for the life cycle?
RNA-dependent RNA pol
In the Hershey-Chase Blender Experiments the S35-labled protein of the bacteriophage was found where in the progeny phages?
Not found
Strain
Genetically stable virus that differs from the parent strain phenotypically
Variant
Virus that contains mutations from the parental strain
Baltimore class that uses a reverse transcriptase
Class 6
Baltimore class that can immediately be translated by ribosomes
Class 4
Viral tropism
Types of cells that a virus can infect
Viral tropism is controlled by
Cell surface receptors
What percentage of the human genome consists of defunct endogenous retroviruses
10
What are some ways viruses resolve the competition between host mRNA and viral mRNA for translational machinery
degrading host mRNAs, contain elements in viral mRNA to increase affinity to ribosome, cleave and obtain host cell mRNA caps
What amendment did Fredricks and Relman make to Koch's and River's criteria for linking a virus to a particular disease
Detection of viral nucleic acids in diseased organs but not in unaffected organs
In a standard clinical virology laboratory setting, which techniques are routinely performed for rapid identification
elisa and pcr
Most antivirals are designed to impair which component of a virus
viral enzymes
What do cells do natural killer cells recognize
cells that show reduced expression of mhc I on their surface
What two major cell types can eliminate viral cells through apoptosis
Natural killer and CD8+ T-cells
Innate immunity
general non-specific defense against pathogens
secondary immune response
immunological memory
phagocytosis
uptake and killing of microbes
What do pathogen recognition receptors do
identify viral pathogens
What do Toll-like receptors do
they are sensors capable of detecting characteristics unique to a virus
Dendritic cells
Express high levels of mhc i and ii molecules and function as scouts to identify pathogens at the body's surfaces and mucosal sites
How do viruses evade host defense
mutate outer surface proteins, latency, inactivate cytokine signaling, inactivate immune cells
Major function of MHC II
presents peptides derived from engulfed viruses
What happens when ds-RNA-activated protein kinase (cellular altruism) is activated in a virally infected cell
Viral RNA degradation and host RNA degradation
Virally infected cell will present foreign antigens on where?
MHC I
Virally infected cells are recognized by which cell type?
CD8
If you were performing a Viral Detection ELISA, what would be coated on your 96-well dish
Antibody specific for viral pathogen
How are live-attenuated viruses produced
a virus is immediately repeatedly cultured in nonhuman cultured cells or animals
What results would indicate the highest viral levels in a RT-PCR
Ct of 10
Prevalence
total number of casesI
Incidence
new cases
Toll-like receptors recognize viral
RNA or DNA
What proteins are secreted following the activation of TLRs
cytokines
Three corners of the epidemiological triangle
host, agent, environment
longitudinal study
study that examines individuals over time
Once ingested polioviruses initially invade which two tissues
peyers patchers or tonsils
what percentage of cases are asymptomatic in polio
95%
Where does the polio lifecycle occur
the cytoplasm
What would happen in the rna genome of poliovirus was transfected or delivered directly in to mouse cells
Rna genome would be translated by host ribosomes into a polyprotein
IRES stands for
Internal Ribosomal entry site