Virology Final Exam
Which statement about viral RNA genomes is correct? - (+)ssRNA genomes may be translated to make viral protein - dsRNA genomes can be directly translated to make viral protein - Copying of (+)ssRNA during virus replication does not require a (-) strand intermediate - RNA genomes can be copied by host cell RdRp
(+)ssRNA genomes may be translated to make viral protein
Which two positive test results would indicate that a patient was previously infected with EBV but that infection has resolved.
- Anti-EBNA Test - Anti-VCA antibody Test
The binding of which host receptor induces the conformational change of the HIV fusion protein?
- CCR5
Which of the following is an advantage of using AAV as a gene therapy vector?
- Can persist in non-dividing cells
Early during infection, which cell type does Ebola virus targets first?
- Dendritic cells
Match the HIV proteins to the order in which it is transcribed.
- Gag protein - Gag-pol polyprotein - Envelope protein
Which of the following viruses are able to infect dendritic cells? Check all that apply. - poliovirus - HIV - Ebola virus - zika virus - rotavirus
- HIV - Ebola virus - zika virus
Which of the following are a human oncogenic virus? Check all that apply.
- Hepatitis B virus - Epstein-Barr Virus
Which of the following are advantages to retroviruses as gene therapy vectors? Check all that apply. - Typically only infects dividing cells - High infection efficiency - Low inflammatory response - Low capsid stability
- High infection efficiency - Low inflammatory response
Which steps of viral vector delivery are shared between Direct delivery and Cell based delivery? Check all that apply. - Insertion of the therapeutic gene into the viral genome - Culturing of viral vector - Injection into the target tissue - Infection of cells within a petri dish
- Insertion of the therapeutic gene into the viral genome - Culturing of viral vector
Which of the following are disadvantages to retroviruses as gene therapy vectors?
- Low capsid stability - Integration can lead to transformation
Which of the following Influenza components are targeted by anti-viral drugs?
- M2 ion channels - neuraminidase
Which of the following characteristics of Measles contribute to the highly contagious nature of the virus? Check all that apply.
- Measles can survive up to 2 hrs in the air and on surfaces - Measles is spread through airborne transmission
Which of the following are symptoms for acute Zika virus infection?
- Microcephaly
Which of the following are activities of the 78/68 protein in AAV replication? Check all that apply. - Nicks the viral genome during DNA replication - Activates transcription of other AAV genes - Serves as a polymerase to make new viral DNA - Aids in packaging of newly synthesized DNA
- Nicks the viral genome during DNA replication
Which of the following are characteristics of the Hepatitis B genome?
- Partially double stranded - circular
Which are similarities between pox virus and herpes virus infectious cycles? Check all that apply.
- Proteins that are involved in the early steps of viral replication are packaged within the viral particle. - Late genes encode proteins for viral structural components
Which of the following viruses are used as vectors for gene therapy treatments?
- Retroviruses - Adenoviruses
3 major pandemics of the 20th century
- Spanish flu - Asian flu - Hong Kong flu
Which of the following are important feature of ssDNA replication?
- The use of host cellular enzymes in DNA replication. - The function of the Rep 78/68 protein.
Which of the following must occur in order for viral envelopes to fuse with cellular membrane during entry?
- The viral and cellular membranes must be pulled together. - The virus must bind it's host cellular receptor. -The fusion protein must undergo a conformational change
Which viral functions (i.e. steps of viral infection) can be targeted by HIV antiviral drugs?
- attachment - penetration and uncoating - DNA/RNA replication - assembly
Why must dsRNA genomes package an RNA-dependent RNA polymerase (RdRp) enzyme?
- bc the enzymes is needed to make mRNA
Which of the following entry mechanisms begins with a virus binding to protein or carbohydrate coated pits? Check all that apply.
- caveolin dependent endocytosis - clathrin dependent endocytosis - clathrin and caveolin independent endocytosis
Which genome are a known viral genome structure?
- circular - ambisense - segmented
Chronological order
- discovery of yellow fever virus - discovery of 1st oncogenic virus - discovery of bacteriophage
Which symptoms are characteristic of early stages of Ebola virus infection? Check all that apply.
- fever - muscle pain - stomach pain - vomiting - headache - diarrhea
Which structure on the viral surface of Influenza is responsible for binding to the host cell receptor?
- hemagglutinin
Which of the following virus families are being developed as an oncolytic virus to treat cancer?
- herpes viruses - parvovirus
Which of the following are signs of viral hepatitis? Check all that apply.
- jaundice - atypical lymphocytes - Increase levels of transaminases in the blood
Which of the following are a human oncogenic virus? Check all that apply. - Ebola virus - karposi sarcoma herpesvirus - human genital papillomavirus - reovirus
- karposi sarcoma herpesvirus - human genital papillomavirus
Types of morphological alterations cytopathic effect
- nuclear shrinking - proliferation of nuclear membrane - vacuoles in cytoplasm - syncytium formation (cell fusion) - margination and breaking of chromosomes - rounding up and detachment of cultured cells
For which of the following viruses is there an inactivated/killed vaccine available?
- polio - hepatitis A - rabies
Which of the following viruses forms a pore in the endosomal membrane in order to release its nucleic acid into the cytoplasm?
- poliovirus - norovirus
Which structural feature of ss(+) RNA genomes allow them to serve as mRNA?
- protein linked to the 5' end - poly-A tails
Which types of viruses use reverse transcriptase (RT) in their replication cycle? Check all that apply. - retroviruses - gapped, circular dsDNA viruses - ss(-) RNA viruses - ssDNA viruses
- retroviruses - gapped, circular dsDNA viruses
Which of the following are modes of transmission for HIV? Check all that apply. - sexual contact - intravenous drug abuse - fecal-oral transmission - respiratory droplets - mother-to-child transmission
- sexual contact - IV drug abuse - mother to child transmission
Which of the following is a distinct step in the reverse transcription of retroviral RNA? Check all that apply. - template exchange - nicking of the template RNA - Initiation of (+) DNA synthesis - Initiation of synthesis of new template RNAs
- template exchange - Initiation of (+) DNA synthesis
During a latent infection which phase of infection is associated with overt symptoms?
- the acute phase - the reactivation phase
Which highlights a primary difference between the replication of dsDNA genomes and gapped dsDNA genomes?
- the gapped genomes uses mRNA as the template for generating new copies of the viral genome
The primary site of infection for varicella zoster (chicken pox) is which of the following?
- the upper respiratory tract
Why are icosahedral shapes the most optimal form of viral capsids?
- they are the most stable form - they provide enough space for the nucleic acid - the use of repeating subunits conserves genetic space
Types of inclusion bodies cytopathic effect
- virions in nucleus - virions in cytoplasm - factories in cytoplasm - clumps of ribosomes in virions - clumps of chromatin in nucleus
Which of the following are examples of how viruses exploit normal cellular function to their benefit? Check all that apply. - Viruses bind to cell surface proteins that have cellular functions outside of being a viral receptor - Viruses uses cellular transport mechanisms to move within the infected cell - Viruses use host enzymes to translate their proteins and copy their genomes - Viruses incorporate cellular RNA into their genomes to aid in antigenic shift.
...
Which of the following viruses does NOT enter the cell through receptor mediated endocytosis? - alphavirus - dengue - VSV - HIV
...
If cells were infected with an MOI of 10, how many bursts of replication would you expect?
1
How many types of Influenza can infect humans?
3
How many types of viral genomes are there?
7
How many segments of RNA does Influenza virus have in its genome?
8
HeLa cells are
A human continuous cell line that has been immortalized as a result of viral infection.
Viral receptors on the cell surface.... - Can bind directly to icosahedral virus capsid proteins - Have cellular functions - Interact with glycoproteins of enveloped viruses - Can be carbohydrate or protein molecules
All of the choices are correct
Which statements about Alphaviruses is FALSE?
Alphaviruses produce a subgenomic mRNA to generate their RdRp.
Which EBV diagnostic test detects antibodies the patient has made against the viral capsid antigen?
Anti-VCA test
Which detection method is best for early detection of HIV?
Antibody-Antigen tests that detect the virus in the blood
Which viruses are the most abundant organism on earth?
Bacteriophage
Why do most RNA containing viruses replicate in the cytoplasm?
Because all of the cellular replication machinery they need is located cytoplasm
Why are parvovirus infections in animals commonly lethal?
Because infections result in dehydration which can lead to death.
Why does immunization against Hepatitis B virus (HBV) reduce the risk of progression to a chronic form of the infection?
Because it stimulate the IgG response against surface antigen
Why must dsRNA viruses package an RNA-dependent RNA polymerase (RdRp) inside their viral capsid?
Because the (+) of RNA in their genome cannot function as mRNA.
In VSV replication, why is mRNA produced before the viral genome is copied for packaging and making new viruses?
Because the viral N protein must be made before a full length (+) strand RNA can be made.
Which is NOT a virus family that is being developed as an oncolytic virus to treat cancer?
Calicivirus
What is the mechanism of entry of Adenovirus?
Clathrin mediated endocytosis
Which of the following does not play a role in virus entry and movement through a cell?
Diffusion of virus particles in the cytoplasm
Which of the following herpes viruses causes mononucleosis disease?
EBV
Which is correct about the history of vaccination against viruses?
Early methods of vaccination were developed in China and India and later brought to England.
Which of the following Picornaviruses is often implicated in accute flaccid paralysis in recent years?
Enterovirus D-68
Which is the first cell type infected by Epstein-Barr Virus?
Epithelial cells
All herpes virus tegument proteins remain in the cytoplasm after uncoating of the virus.
False
All types of HPV are equally capable of resulting in cancer formation.
False
Antiviral drugs against Influenza that target M2 ion channel inhibit infection by preventing the ability of newly formed viruses to spread to other cells.
False
Cellular enzymes are responsible for cleaving apart the multiple copies of dsDNA made during rolling circle replication.
False
During chicken pox infection, skin lesions result from the primary viremia.
False
During viral infection, the viral genome is copied before the viral mRNA is translated.
False
HIV uses viral polymerases to make copies of its genome.
False
Hepatitis C virus is directly responsible for hepatocyte cell death.
False
Herpes simplex virus can only be spread by symptomatic patients.
False
Host cell receptors are highly specific for a single virus.
False
Host enzymes cleave the viral polyprotein into individual proteins.
False
Influenza virus was discovered before the first oncogenic virus was discovered.
False
Maturation of the HIV virus occurs before the virus buds off from the host cell.
False
Most antiviral drugs target genome replication machinery.
False
Oncolytic viruses can have their surface proteins modified to change the cells they recognize, but they will still infect both normal cells and cancer cells.
False
People can only transmit Influenza if they are actively experiencing symptoms.
False
Replication of the genome of ss(+)RNA viruses is not associated with vesicles. NOTE: Do not take retroviruses into consideration when answering this question.
False
Resistance to neuraminidase inhibitors develops frequently in Influenza viruses.
False
Resistant cells cannot support viral replication.
False
Rotavirus causes bloody diarrhea.
False
The HIV RNA genome is released from the capsid directly into the nucleus.
False
The Hepatitis C virus diagnostic EIA test is an antibody based assay that can detect HCV as early as 2 weeks after infection.
False
The ability of viruses to grow and replicate outside of their host cells is a characteristic that makes them highly infectious and is important for transmission.
False
The coordinated regulation of herpes virus infection is controlled by host proteins in response to the production of VP16.
False
The initial adherence of viruses to host cells are guided by electrostatic forces and are extremely specific.
False
The mRNA made generated from the Influenza virus genome segments are full length copies of the genomic RNA.
False
The rotavirus genome gets released into the cytoplasm prior to the generation of mRNA.
False
The timed expression of genes within the herpes virus genome is controlled by host cellular proteins.
False
Viral enzymes packaged in the viral particle are used to convert ssDNA viral genomes into double stranded DNA.
False
Virally transformed cells are characterized by increased production of viral particles.
False
ss (-) RNA viruses encodes for poly proteins.
False
ss(+) RNA viruses package an RNA-dependent RNA polymerase (RdRp).
False
ss(-) RNA viruses make new viral genomes from their mRNA.
False
ssDNA viruses only package a (+) strand of DNA into new viral particles.
False
Zika virus
Flaviviridae
Which of the following is not a class of viral genomes? - (-) ssRNA - Gapped dsDNA - Gapped dsRNA - (+) ssRNA - dsDNA
Gapped dsRNA
Inverted terminal repeats form which important structures of linear ssDNA molecules?
Hairpin structures
Hepatitis B family
Hepadnaviridae
How are vaccines able to prevent disease in a population even if they are not 100% effective?
If the herd immunity threshold for a virus is reached with vaccination, the entire population will be protected.
During mRNA synthesis, specific regions of the VSV genome cause the RdRp to stop making mRNA. What is the name of that region?
Intergenic region (Ig)
Which T cell count is used to mark the formation of Acquired Immune Deficiency Syndrome (AIDS)?
Less than 200 T cells/mm3
Which of the following is NOT an area of the body that can be infected by non-polio Enteroviruses? - Skin - Heart - Central Nervous System - Eyes - Liver
Liver
Which protein is responsible for controlling the switch between making mRNAs and making genome for Influenza virus?
Np protein
Human Adeno-Associated Virus (AAV) Family
Paroviridae
The titer or concentration of a virus stock can be measured using a plaque assay and is calculated in....
Plaque forming units (PFU) per milliliter
What enzyme comes packaged in the Influenza viral capsid, attached to the (-) RNA segments?
RNA polymerase
Which enzyme is used by RNA viruses to synthesize mRNA?
RNA-dependent RNA polymerase
Which activity of the polymerase is responsible for degrading the pre-genomic RNA during Hepatitis B DNA replication?
RNase H activity
Which best describes the course of a chronic infection?
Rapid increase in virus concentrations after infection that remain high throughout the life of the host.
Shingles is an example of which type of infection?
Reactivated latent infection
In which way is the retrovirus HIV, unlike other single stranded, positive sense (+), RNA viruses.
Retroviruses encode an RNA transcriptase (RT) to convert their RNA to DNA
The Hepatitis B polymerase performs three functions in the formation of new genomic DNA. Which of the following answer choices shows the correct order in which these functions occur?
Reverse Transcription, DNA Synthesis, Priming
Which of the following is the proper sequence of events in HIV replication?
Reverse transcriptase converts HIV RNA into DNA, Integrase transports the new DNA to the nucleus and integrates it into the host chromosome and the viral genome gets translated to mRNA when the host transcribes its own RNA.
One day you find yourself sick with both diarrhea and vomiting. Since you've taken Virology, you know that you are likely infected with either Norovirus or Rotavirus. Which aspect of your illness or symptoms would give a good indication of which virus you were infected with?
Rotavirus is a pediatric disease, so I most likely have a Norovirus infection.
Which of the following is the key marker for Hepatitis B infection?
Surface antigen (HBsAg)
For ss (+) RNA viruses, which protein is responsible for copying the genome?
The RNA-dependent RNA polymerase (RdRp)
Which of the following are true of viral infection?
The receptors molecules on the surface of the virus determine which type of cells the virus can infect
Which step is found in Dengue virus replication but not Poliovirus replication?
The viral RNA forms a circle prior to joining with the replication complex
Which of the following are a reason that ssDNA viruses rely heavily on the use of host cellular enzymes?
Their viral genomes are so small they don't encode many replication proteins.
Which of the following statements are true of all viruses? - They all have a protein capsid that encases their genetic material - they are all enveloped - all the answer are correct - they all possess the same type of nucleic acid
They all have a protein capsid that encases their genetic material
Which is NOT a characteristic of viral nucleic acids?
They are always double stranded
Why are adjuvants sometimes added to vaccines?
To help enhance the immune response against the antigen found in the vaccine
A primary function of the capsid is to protect the viral genome.
True
Antiviral drugs that target the M2 ion channel of Influenza function by inhibiting RNA release from the endosome into the cytoplasm.
True
Both Pox and Herpes viruses have linear, ds DNA genomes.
True
Both carbohydrate and protein receptors on host cells can be used by viruses as attachment receptors.
True
Cell death from viral infection can be caused by either the virus or the host.
True
Dengue viruses acquires its envelope from the endoplasmic reticulum.
True
Ebolavirus fusion protein specifically binds the NPC1 protein inside the endosome.
True
For some enveloped viruses that enter through membrane fusion, like Measles Virus, the entry and uncoating processes are linked.
True
HIV uses host polymerases for production of viral mRNA.
True
Herpes viruses can infect the central nervous system.
True
Human parvovirus infection is much less severe than animal parvovirus infection.
True
In Hepatitis B replication, cellular enzymes are responsible for generating mRNA.
True
In general, HSV 2 tends to infect and cause symptoms below the waist.
True
Reoviruses are one of the few viruses that never fully uncoats.
True
Retroviruses are able to carry mutated genes from one cell to another and cause cellular transformation.
True
Retroviruses differ from other ss (+) RNA viruses in that their genomes are NOT directly translated into proteins.
True
Retroviruses replicate independently of the host chromosome replication.
True
Some Influenza mRNAs encode for multiple proteins.
True
The Fc receptor is involved in antibody dependent enhancement of Dengue infection.
True
The cellular origin hypothesis of the evolution of viruses states that viruses evolved from escaped nucleic acids.
True
The host response to viral infection can be responsible for some of the disease symptoms.
True
The lowering of internal pH is a major difference between endosomes and caveosomes.
True
The lytic and lysogenic cycles for bacteriophage begin in the same way but have different outcomes.
True
The primary infection of oral herpes often results in disease symptoms that are more severe than the symptoms of recurrent infections.
True
There are some viruses that only encode 1 viral protein.
True
Unlike ss(-) RNA viruses, the mRNA of Reoviruses are full length copies of the viral genome.
True
VSV structural proteins are made by ribosomes that are bound to the endoplasmic reticulum.
True
Viral capsids and glycoproteins often undergo a conformational change when they interact with their host cell receptor.
True
Viral capsids are generally made from a small number of structural subunits that are repeated to form a regular, symmetrical structure.
True
Viral enzymes nick the Pox virus genome to initiate DNA replication.
True
how does translation of VSV differ from translation of Poliovirus?
VSV translates each protein sequence individually while Poliovirus translates one long polyprotein that is ultimately cleaved by viral proteases.
What contributes to the cyclical nature of Norovirus outbreaks?
Viral evolution and the emergence of new viral strains
The term for the one long protein that results from the translation of the picornavirus genome is...
a polyprotein
attenuated
a reduced level of virulance where symptoms are mild or inconsequential
If cells are infected at an MOI=10 in a one step growth cycle experiment, in the growth curve you will see...
a single burst of virus release
Which of the following is an example of horizontal transmission?
acquiring a viral infection from touching a contaminated door knob
Of the viruses used in gene therapy discussed in the lecture, which can be easily grown in cell culture?
adenoviruses
Of the viruses used in gene therapy discussed in the lecture, which can be easily grown in cell culture? - retroviruses - adenoviruses
adenoviruses
Measles virus mode of transmission
airborne transmission
Rabies virus mode of transmission
animal bites
Co-infection of the same cell with multiple viruses can potentially lead to a large genome re-assortment resulting in ______________.
antigenic shift
During rolling circle replication cellular enzymes will repeatedly sit down on the newly synthesized strand of DNA to make the second strand of the dsDNA genome. This process is termed.....
asynchronous DNA synthesis
Uncoating of the viral nucleic acid occurs...
at or near the site of nucleic acid replication.
Which characteristics of gene therapy viruses, allows scientists to overcome the issue of immune responses developed against a virus?
availability of multiple serotypes
Prolate is a viral shape variant found in
bacteriophages
The phase of a virus growth curve where virus concentration is rapidly increasing is called the...
burst period
How is Hepatitis B virus transported through the cell to the nucleus after entry?
by microtubules
Which of the following are an advantage of using immortalized cell lines to grown and study viruses?
can be passed indefinitely
hepatitis c
cancer
The protein structure surrounding the viral nucleic acid is called the....
capsid
The building blocks of the viral capsid are
capsomeres
Which type of infection is characterized by rapid increase in virus concentration that is maintained at a high level for the life of the host?
chronic infection
Which of the following is an outcome that can result from chronic Hepatitis C infection?
cirrhosis
What is not characteristic of transformed cells?
contact inhibition
At what cellular location do most RNA containing viruses replicate?
cytoplasm
Which characteristic of Measles infection is linked to development of immune amnesia?
destruction of memory immune cells
Which DNA genome, upon entry into the cell, can be immediately copied into mRNA?
dsDNA
Which phage encoded enzymes is responsible for cleavage of the peptidoglycan in the bacterial cell wall to allow for lysis and phage escape?
endolysin
Glycoproteins are found on the viral _________.
envelope
Which lentivirus proteins are generated from a spliced RNA?
envelope proteins
During persistant infection, which cell type is most widely infected by noroviruses?
epithelial cells
Adeno-associated virus (AAV) is being explored as a vector for gene therapy in part because of it's large genome capacity.
false
All retroviruses have icosahedral shaped nucleocapsids
false
The term for incorporation of bacteriophage into a bacterial host chromosome is called latency.
false
Which of the following are NOT a virus family that is being developed as an oncolytic virus to treat cancer?
flavivirus
What are the primary cellular genes targeted during viral infection that lead to cellular transformation?
genes that are involved in controlling cellular replication
Which of the following assays should be used for quantifying viral particles in a time sensitive sample?
genetic assay
Which Hepatitis C genotype had the lowest response rate to interferon and Ribovirin?
genotype 1
Which viral protein is used to bind to the CD4 receptor?
gp120
Which of the following is not a concern when using phage therapy to treat bacterial infections? - phage-host range limitations - high-toxicity of phages to humans - phage selection - unfamiliarity with phages
high-toxicity of phages to humans
Infection efficiency
how well a virus infect a given cell
Rhinovirus
inconvenient illness
Of the viruses discussed in the course, which encode both a hemmaglutinin and a neuraminidase?
influenza
Which is a unique characteristic of Influenza replication in comparison to other RNA viruses?
influenza RNA goes into the nucleus for transcription
Allantoic inoculation of embryonated chicken eggs with is still a commonly used method of generating the virus today.
influenza virus
variolation
inoculation of a healthy individual with a small amount of a viral pathogen through a scratch on the skin
vaccination
inoculation of healthy individuals with less virulent forms to produce immune response
Which viral enzyme is directly involved in incorporating HIV DNA into the host chromosome?
integrase
Which of the following types of proteins are expressed early in the lysogenic cycle of bacteriophage?
integrases
How is the influenza vaccine unique in comparison to most other vaccines?
it has to be reformulated every year
Ebolavirus
life threatening
No viruses encode these proteins
lipid membrane synthesis
Which event induces fusion of the Influenza envelope with the endosomal membrane to release the viral genome into the cytoplasm?
lowering of the endosomal pH
The use of which nucleic acid is common to all viral replication schemes?
mRNA
Waning of herd immunity has resulted in a resurgence of which of the following viruses?
measles
What is the classic mechanism for pox virus entry into cells?
membrane fusion
Which area of the body is the first site of Rabies virus replication?
muscle cells
Which is a disadvantage of phage therapy?
narrow host range
Which of the following viruses cause both vomiting and diarrhea upon infection?
norovirus and rotavirus
All viruses encode these proteins
packaging of the viral genome
Which of the following laboratory techniques is used to quantify infectiousviral particles?
plaque assays
Which of the following viruses generates a polyprotein during translation?
poliovirus
Which two viruses provide excellent examples for how vaccines are able to dramatically reduce disease in a population?
poliovirus and measles virus
"Susceptible" is a term used to describe cells that
possess a functional viral receptor
A virus that is integrated into the host genome is called a ________.
provirus
Which of the following vaccines can be given after infection and still be effective at preventing disease?
rabies vaccine
For which virus was the first deliberately attenuated viral vaccine developed?
rabies virus
Which ss(-) RNA virus has a 100% mortality rate?
rabies virus
Some viruses encode these proteins
release and spread of the virus
Which of the following is a difference between clathrin-dependent and caveolin-dependent endocytosis?
release of the viral nucleic acid from the caveosome is a pH independent process
HIV mode of transmission
sexual contact
What is the most common mode of transmission for HIV?
sexual contact or intercourse
What molecule on the host cell does Influenza virus bind to?
sialic acid
Zika virus genome
ss (+) RNA
Rabies virus genome
ss (-) RNA
Parvovirus genome
ssDNA
Which of the following must describe a cell in order for a virus to use it for the entire replication process?
susceptible and permissive
What key concept about viruses was demonstrated by the Hershey-Chase experiments?
that nucleic acid were the genetic material of viruses
Fusion of the Ebola virus envelope with the endosomal membrane differs from other viruses that use this mechanism in what way?
the Ebola fusion protein binds specifically to the host receptor NPC1
Stability of gene expression
the ability of a delivered to be expressed for extended periods of time
Pathogenicity
the ability of the virus to cause disease
Resting cell infection
the ability to infects cells that are not actively dividing
At what site on the ssDNA genome do host polymerases bind to initiate DNA synthesis?
the origin of replication
What property of cells, particularly stem cells, makes cell based delivery possible for viral vectors?
their homing properties
Which of the following is an advantage for using inactivated/killed vaccines?
there is no risk of viral reactivation
Which was the first viral characteristic discovered that distinguished viruses from other microorganisms?
they were small enough to pass through filters
Which of the following types of proteins are encoded by all viruses?
those used for assembly or packaging of the genome
What is the name of the HSV enzyme that modifies the pro-drug acyclovir to make it functionally active?
thymidine kinase
When doing a plaque assay, what is the purpose of adding a semi-solid agar overlay on the monolayer of infected cells?
to restrict viral diffusion after infection
Which is the first step in the formation of cancer (also called oncogenesis)?
transformation
Immortalized cell lines are easier to use than primary cells but are less biologically relevant.
true
In order for the Influenza genome to be released into the cytoplasm the internal pH of the virus must lower and this is facilitated by the M2 ion channel.
true
Infection by certain viruses can lead to cancer but don't directly cause cancer.
true
Oncolytic viruses can be modified in such a way that they are able to infect both normal and cancerous cells but will only replicate in the cancer cells.
true
Retrovirus integration into host chromosomes is not sequence specific
true
The molecule in a vaccine that an immune response is generated against is called what?
vaccine antigen
Which of the following is not a type of inclusion body? -vacuoles in the cytoplasm - virions in the nucleus - virions in the cytoplasm - "factories" in the cytoplasm
vacuoles in the cytoplasm
Which of the following statements is TRUE. - viral enzymes are responsible for cleaving the polyproteins of Flaviviruses - flaviviruses generate individual mRNAs for translation - cellular enzymes are responsible for cleaving the polyproteins of Flaviviruses
viral enzymes are responsible for cleaving the polyproteins of Flaviviruses
Which conclusion can be made about a sample when using only PCR technology to detect viruses?
viral nucleic acids are present in the sample
What is the term for the community of viruses that colonizes the human intestinal tract?
virome
A person acquiring a viral infection after being bitten by a mosquito is an example of what type of transmission?
zoonotic transmission