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