Virology Final Study Guide - BIO 3442

Describe how Orthomxyoviruses replicate. Begin with the release of nucleocapsids from endosomes into the cytoplasm and end with new nucleocapsids in the cytoplasm ready to be packaged.

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Discuss temporal regulation of bacteriophage T7 protein expression. Include in your discussion any factors that would contribute to temporal regulation as well as any role that transcription may play

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Polio is a highly infectious disease that can cripple and even prove fatal for those who become infected. To combat this The Poliovirus Global Eradication Campaign was initiated in 1988 by the WHO. Describe the poliovirus vaccines currently available and the pros and cons of each in regard to global eradication. Be sure to include VAPP and VDPV in your discussion.

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Using the Baltimore classification system explain what proteins are required for the following viral genomes to synthesize mRNA: dsDNA, ss(-)RNA, ds gapped DNA, ss(+)RNA, ssDNA

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Why do many viral fusion proteins require proteolytic cleavage? Give an example of a viral fusion protein and the protease cleaved required for cleavage.

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List three aspects of HIV's biology that makes it an extremely difficult virus for the human immune system to eliminate.

1-10 mutations per virion leads to gradual selection for resistance; uses receptors on helper Th cells (CCR5, CD4+) and degrades Th cells; latent/inactive infection does not activate immune response; can induce chronic immune response that exhausts T cells; integrates into DNA

List the steps of the replication cycle of retroviruses:

1. Reverse transcription of viral genome into dsDNA. 2, Integration into host cell DNA 3. Transcription of viral genome in mRNA 4. Translation of viral genome 5. Replication of host genome into daughter molecules

Which of the following molecules is the activator for ribonuclease L, which is part of the interferon induced antiviral pathway?

2' 5' -oligo(A)

Influenza produces 11 different proteins from 8 genome segments. How many of those proteins are packaged into the viral particle?

9

If a purified poxvirus genome was heated to melt the hydrogen bonds holding the two strands of DNA together, which of the following would describe the structure of the genome?

A circle of single-stranded DNA

Which of the following describes the form that the papillomavirus genome is found in most cervical cancer cells?

A fragment of the genome is integrated into the genome of the host cell.

Which of the following is the best description of syncytia?

A fusion of two cells caused by viral envelop glycoproteins.

B cells

Activated by binding to antigens via B cell receptor; differentiate into plasma cells

Cleavage of the HA protein of influenza by cellular proteases is important for which of the following?

Activation of the fusion peptide

Which of the following describes the process of RNA editing as used by the paramyxoviruses?

Addition of one or two non template nucleotides to the mRNA

terminal protein

Adenovirus

Explain antibody-dependent enhancement in the context of dengue hemorrhagic fever.

Antibody enhancement occurs when a host has already been infected by dengue virus, host recovers and developed antibodies but then gets infected a seconds time by a different but similar strand. The second infectious virus will be recognized my antibodies and carried to microphage but they don't fit well so the virus falls off and can replicate in the macrophage totally avoiding the immune system

Explain the difference between antigenic drift and antigenic shift.

Antigenic drift is a gradual single point mutation of the strain resulting in seasonal epidemic (influenza A). Antigenic shift is the process by which two or more different strains of a virus, or strains of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains.

Hendra outbreaks have been seen in...

Australia

The majority of known coronaviruses have been isolated from which of the following vertebrates?

Bats

Which of the following statements about why bats are a reservoir for so many viruses is FALSE?

Bats have no immune system so cannot fight off viral infection

Dendritic cells

Bind to antigens and virus particles; antigen presentation to T cells

Which of the following can induce the extrinsic apoptosis pathway?

Binding of TNF-a to the cell surface receptor

What mechanism do the paramyxoviruses use to produce 5 different proteins from a single gene in their genome?

Both RNA editing and alternative start codons are used

How are the genes in the genome of the bacteriophage T7 arranged in the genome?

By when they are expressed during the viral replication cycle.

All prion associated diseases are confined to which of the following organ systems of the body?

CNS

Which of the following statements about rhinovirus is incorrect?

Causes lower respiratory tract infections

Papillomavirus causes

Cervical cancer

Which of the following is a FALSE statement regarding Chikungunya virus?

Chik virus is classified as a coronavirus

Bacteriophage T7 was isolated from what source?

Commercially available treatment for intestinal infections.

Which of the following conditions during infection with a paramyxovirus causes the RNA-dependent RNAP to switch from start-stop transcription to production of full length positive-strand antigenomes?

Concentration of the N protein

Which of the following is the first step in the expression of reovirus proteins during the infection?

Copying of the negative strand of each segment into an mRNA

MERS-Co-V

Coronavirus

The VP30 protein from Ebola virus activates synthesis of the NP mRNAs by doing which of the following?

Counteracts the negative effects of a stem-loop at the 5' end of the mRNA

Which of the follows NOT a professional antigen presenting cell?

Cytotoxic T lymphocyte

Which of the following is not a component of the innate immune response system?

Cytotoxic T lymphocytes

An Ebola virus outbreak began in December 2013. Explain how and where the outbreak began, explain the key factors (environmental, cultural, etc.) that have contributed to the spread of the outbreak, identify where it has spread and why it has been difficult to contain.

December 26, 2013- 2 year old boy fell sick in remote Guinean village of Meliandou - Fever, black stools, vomiting - Died 2 days later • Disease continued undetected causing several chains of deadly transmission • First 14 cases died - High risk exposures • Caring for sick relative • Preparing body for burial • Delivering a baby • No doctor or health official here had ever seen a case of Ebola- No alarms went off • Area often sees outbreaks of endemic diseases = cholera, malaria, other infectious diseases

Which of the following is an accurate description of autophagy?

Degradation of cellular components in a phagosome.

What are the professional antigen presenting cells?

Dendritic, B lymphocyte, Macrophage

Which of the following diseases do mosquitoes spread?

Dengue Fever

Which of the following proteins from papillomavirus can bind to the viral origin of DNA replication and unwind the DNA strands?

E1

Which of the following components of the toga virus virion bind to host cell receptors?

E2 glycoprotein

Flavivirus virions obtain their envelopes from the cellular membranes of which of the following organelles?

ER

Which of the following two herpesviruses have been associated with human cancers?

Epstein-Barr virus and Kaposis sarcoma virus

The Avian Influenza (H7N9) detected in China in 2013 involved reassortment of viruses from all but which of the following?

Eurasian Swine

Antibodies are produced by CD4 positive T lymphocytes.

False

Herpesviruses hardly ever cause serious or fatal infections, even in patients with reduced immune systems

False

Most DNA viruses replicate in the cytoplasm of the host cell, since the ribosomes they need are located in this cellular compartment.

False

Both RIG-1 and TLR-7 are membrane bound proteins that can bind to single-stranded viral RNA.

False.

Ebolavirus

Filovirus

What is the inflammatory response process?

First, accumulation of leukocytes at the site of infection. This leads to the local activation of antimicrobial functions and the production of cytokines. This in turn increases vasodilation and capillary permeability. The leukocytes spontaneously phagocytose virus particles or debris from virus infected cells. The process is enhanced by complement binding or antibody binding to virus particles. Phagocytic vesicles fuse with lysosomes and degradation of viral particles occurs.

What are some of the diseases caused by a member of the picornavirus family?

Foot/mouth, polio, common cold, HepA

Inclusion bodies inside the cytoplasm of cells infected with Ebola virus are sites for which of the following processes?

Formation of viral nucleocapsids

Which of the following cellular proteases helps to process the polyprotein of flaviviruses?

Furin

The index case for the current ebola outbreak in W. Africa lived in which of the following countries?

Guinea

Describe the important viral protein-cell protein interactions that occur between high-risk papillomaviruses and host cells that can lead to cancer formation.

HPV16 and HPV18 are two of the higher risk HPV responsible for the formation of cancer in humans. Their infection of basal epithelioma cells in the human cervix is crucial. Within these differentiated keratinocytes, HPV encounters a problem. These cells are not actively dividing. Inducing division will also activate defenses resulting in cell cycle arrest or apoptosis. Thus, the virus employs E7 to induce cell cycle division by Rb, retinoblastoma gene present in most tumors. Then to prevent p53 from halting mitosis or entering apoptosis, E6-complex binds to p53 and degrades it, allowing for proliferation of cell(s).

Describe what happens during a primary infection with HSV1, how the virus enters into latency, and then how the virus can be reactivated back to a lytic infection.

HSV1 initially infects cells in the oral mucous. During this primary infection, viral replication is high and virions proliferate these cells. In latency, the virion is stored in the nucleus of neurons. The virus is reactivated in times of high stress or from UV light, and the virions travel down the axon and reinfect the epithelial cells. This produces lytic infection anew.

Which of the following describes the structure of the coronavirus virion?

Helical nucleocapsid surrounded by an envelope.

tegument

Herpesvirus

Both HSV and EBV, which are members of the herpesvirus family, have mechanisms that prevent the immune system from recognizing and killing infected cells. Which of the following explains why this is important?

Herpesviruses are maintained in the host for life in a latent infection

All of the following are distinct features of the reverse transcription process, used by retroviruses to convert their ssRNA genome into a dsDNA provirus, except

Host DNA polymerase is responsible for replication of the complementary positing strand of DNA.

What does the term quasi-equivalent mean with respect to the proteins in an icosahedral capsid?

If the identical protein is used, it has both 5 and 6 fold interactions with the other proteins

The alpha genes of herpes simplex are expressed at which time point during the viral replication cycle?

Immediate-early

An experiment was done in toga viruses where the nsP2 protein was mutated so that it can proteolytically cleave the P123 protein very quickly. Which of the following describes the results of this experiment?

Inability of the virus to produce negative-strand genomes

The small T antigen of SV40 regulates the cell cycle of the host cell by DIRECTLY doing which of the following?

Inhibiting the activity of the PP2A phosphatase

Which of the following describes the second step in the replication cycle of retroviruses?

Integration of the viral genome into the host cell DNA

What are the types of cytokines?

Interferons (first produced); pro inflammatory cytokines (IL-6, IL-12, TNFalpha; activate immune cells); chemokine (recruit lymphocytes and Ag presenting cells); anti-inflammatory cytokines (suppress and return immune system to rest)

Which of the following describes the function of the VP16 protein from herpes simplex virus?

It activates transcription of immediate early genes.

The VPg protein from picornaviruses has which of the following function?

It acts as a primer for RNA synthesis.

Which of the following describes the function of the M2 protein from influenza virus?

It acts as an ion channel to allow H+ ions to enter the virion.

Which of the following describes the function of the terminal protein in the replication of the genome of adenovirus?

It acts as the primer for DNA replication

How has the creation of reassortment viruses helped in the study of reoviruses?

It allows for the association of a specific viral protein with its function.

What is the enzymatic function of the RNaseH activity of reverse transcriptase?

It degrades RNA in an RNA:DNA hybrid.

What is unusual about the structure of the genome of herpes simplex virus?

It has two unique sequences flanked by inverted repeats.

When it was discovered, what was surprising about the gene that codes for the prion infectious agent?

It is found in the genome of the host

How does cleavage of the host cell protein eIF-4G give the virus a competitive advantage?

It prevents translation of host cell mRNAs but not viral genomes

What is function of cleavage of the mRNAs from bacteriophage T7 by the host ribonuclease III?

It processes the transcript into smaller more stable mRNAs

What is the role of the viral RNAP in the replication of the T7 genome?

It produces RNA primer on the leading strand

SV40 virus was found as a contaminate of which vaccine and why was it of concern?

It was in the the polio vaccine. There was no report of an increase in tumor or cancer incidence.

In terms of virulence, which type of virus would be associated with the earliest of human populations and why?

It's -ssRNA because humans are most susseptable and fatalities are higher so they have co evolved with us in evade out a immune system well

Human Herpesvirus 8 causes

Kaposis' sarcoma

The gene regulation cascade of poxviruses is controlled by virus produced transcription factors. At what point in the virus replication cycle is the viral early transcription factor synthesized?

Late

Which of the following factors affect the abundance of the viral proteins produced during infection with a reovirus?

Length of the mRNA, sequences surrounding the start codon, length of the 5' noncoding sequence, and secondary structure in the 5' noncoding sequence. (All of the above)

Which of the following proteins from paramyxovirus virions interacts with the tails of the envelope glycoproteins during assembly of virions?

M protein

The nonstructural proteins of flaviviruses are produced on the rough ER and have membrane spanning domains. Which of the following explains why the nonstructural proteins are localized to cellular membranes?

Membranes serve to localize the viral replication complex.

Polyomavirus causes

Merkel cell carcinoma

Synthesis of mRNAs in paramyxoviruses occurs through a single-entry mechanism, which is where the RNA-dependent RNAP can only start transcription from the 3' end of the genome. Which of the following is a consequence of this mechanism?

More mRNA is produced from the coding regions at the 3' end of the genome.

Many viruses reduce the amount of MHC-1 complex on the surface of the infected cell. How does the immune system recognize cells that lack MHC-1?

NK cells will kill cells that lack MHC-1 on the surface .

The abundance of which of the following proteins from influenza virus controls whether the virus is producing mRNAs or full-length positive antigenomes.

Nucleocapsid protein

Which of the following is a difference observed between paramyxoviruses and rhabdoviruses?

One fuses the envelope at the PM and the other fuses envelope with ER

How does a toga virus ensure that only full length genomes are packaged into the virions?

Only full length genomes contain the packaging signal

Influenza virus Type A

Orthomyxovirus

Which of the following events during assembly of herpesvirus virions causes the scaffolding proteins to be ejected from the capsid?

Packaging of viral DNA into the capsid.

Measles virus

Paramyxovirus

Which of the following is an enzyme that most RNA viruses encode in their genome?

RNA dependent RNAP

Which of the following enzymes is not involved in replication of T7 genome?

RNAP

All of the following viruses are found in the Paramyxoviridae family except....

Rabies virus

NK cells

Recognize abnormal infected or cancer cells lacking surface MHC; induce apoptosis

During infection with adenovirus which of the following events activates the production of the major late transcripts?

Replication of the viral genome

Which of the following viruses has NOT been associated with lethal human disease?

Reston virus

Which of the following members of the toga virus family is not transmitted via mosquitoes?

Rubella virus

Which of the following coronavirus emerged as a serious human pathogen in Asia in 2003?

SARS-CoV

Which of the following coronavirus proteins is responsible for virus entry and is the primary determinant of host range?

Spike (S) protein

Which of the following is not being used for treating Ebola infection in West Africa?

Steroids

List effects of interferon on the immune response.

Stimulates antigen processing and presentation; facilitates Th1 cell production; stimulates macrophage activation; influences Ig phenotype switching

Plasma cells

Synthesize and secrete antibodies

Which of the following is found on the surface of the host cell or on endosomal membranes and can recognize viral nucleic acids?

TLRs

Herpes virus contains a large amorphous mass between the envelop and the capsid. What is this material called and what is its composition?

Tegument, VP16 and Vhs are components crucial to viral success. VP16 is responsible for early transcription. Vhs is responsible for overproduction of viral mRNA, the repression of cellular messenger and overall success.

During infection with a toga virus, the subgenomic mRNAs represent the complementary strand of which of the following?

The 5' half of the negative strand antigenome

If the histone proteins are removed from genome of SV40, which of the following will happen?

The DNA becomes supercoiled

Cervical tumors caused by human papillomavirus do not show the typical mutations in the p53 gene that most cancer cells have. Which of the following explains why?

The E6 protein causes the degradation of the p53 protein.

A Type I membrane protein has which of the following structures?

The N-terminus faces outside the virion and the C-terminus faces the inside.

Which of the following describes an interesting feature of the reovirus virion?

The capsid consists of two concentric shells, bot with icosahedral symmetry

Which of the following must occur in non permissive cells which become transformed by the polyomavirus SV40?

The early viral genes become integrated into the host chromosome.

If the genome of a +RNA virus (not retro) which has been purified away from all of the virion proteins, was injected into the cytoplasm of an appropriate host cells, what would happen first?

The genome would be translated by cellular ribosomes.

Which of the following primarily determines the species and type of cell infected by a retrovirus?

The host cell receptor found on the cell

Why do many positive strand RNA viruses form their genome replication complexes on the surface of cytoplasmic membranes?

The membrane acts as a nucleation site to bring all of the proteins together.

The open reading frame that takes up the 5' end of the toga virus genome encodes which of the following?

The nonstructural proteins

Which of the following explains why there is a gap in the DNA genome of hepB virus?

The polymerase enzyme runs out of deoxynucleotide triphosphate.

Which of the following observations about the PrPSc protein could explain how this protein causes damage to the neurons of the brain?

The protein aggregates to form fibrils.

What is the structure of the ends of the adenovirus genome when it is released from the virion into the nucleus?

The terminal protein is covalently bound to the 5' end

There are two sequence elements at the 3' end of the genomes of paramyxoviruses that are required for mRNA transcription and genome replication. These two sequences are 78 nucleotides apart. How can the polymerase bind to boo of these sequence elements at the same time?

The two sequences are both on the same side of the helical nucleocapsid

How is the poly (A) tail added to the 3' ends of the mRNAs produced during infection with an influenza virus?

The viral polymerase stutters at a poly(U) sequence

Papillomaviruses replicate in differentiated keratinocytes, which are not actively dividing. How does the virus handle this situation?

The viral protein E7 binds to the pRb protein, forcing the cell into S phase.

The poliovirus protease cleaves the cellular eIF-4G protein. Why doesn't this affect the virus?

The virus does not use cap-dependent translation

Which of the following statements is incorrect regarding Nipah virus?

The virus has been associated with camels.

SV40 induces the infected cell to enter the S phase of the cell cycle. What purpose does this serve for the virus?

The virus requires the DNA replication enzymes made during the S phase

Which of the following is a true statement about SARS-CoV?

There have been no reported cases of infection with SARS-CoV since 2004

Poxviruses produced two distinct types of virions. Which of the following describes the primary role of the mature virion?

They are transmitted between hosts.

Which of the following is a likely purpose for the noninfectious particles produced by hepB virus?

They bind to antibodies allowing the virus to evade the immune system.

Some picornaviruses have depressions called canyons on their surface. Which of the following describes the role these play?

They bind to the host cell receptor

Which of the following statements comparing HepA with HepC is FALSE?

They both can be spread by infected blood transfusions

All of the following describe similarities between the reverse transcription process in retroviruses and hepandnaviruses except:

They both use a protein primer to begin DNA synthesis.

Since translation of mRNAs in eukaryotic cells produces only a single polypeptide, how do picornaviruses produce multiple proteins from their RNA genome?

They cleave a single polypeptide into individual proteins.

Poxviruses produced two distinct types of virions. Which of the following describes the primary role of the extracellular virus particle?

They infect new cells and tissues within a single host.

When the late promoter of papillomaviruses is activated, it increases production of the E1 and E2 proteins. Which of the following explains why an increase in these two proteins would contribute to vegetative replication of the virus?

They initiate DNA replication of the viral genome.

Most retroviruses, with the exception of lentiviruses, can only infect cells that are actually dividing. Which of the following explains the primary reason for this?

They need the cell to undergo mitosis so the viral genome can enter the nucleus.

How are the structural proteins in toga viruses expressed?

They re translated from a subgenomic RNA

Which of the following describes the major distinguishing feature of poxviruses when compared to other DNA containing viruses that replicate in eukaryotic cells?

They replicate exclusively in the cytoplasm of infected cells

The E1A protein from adenovirus indirectly stabilizes the cellular p53 protein. Why is this potentially a problem for the virus?

This will induce apoptosis pathway, which leads to cell death.

What are the primary lymphoid organs?

Thymus and Bone marrow

The RNA polymerase from bacteriophage T7 has become a useful tool in molecular biology. Which of the following describes how it can be used?

To express high levels of foreign protein in a bacterial cell.

Rubella virus

Togavirus

The TRS sequence on the coronavirus genome is involved in which of the following processes?

Transcription of the subgenomic negative strands

The papillomaviruses used to be classified in the same family as the polyomaviruses. Which of the following is a feat that distinguishes them from polyomaviruses?

Transcription of their genome only occurs on one strand.

The entry of the genome of the bacteriophage T7 is dependent on which of the following processes?

Transcription of viral genes by the host RNA polymerase

Which of the following is the general term used to describe the type of disease caused by prions?

Transmissible spongiform encephalopathy

Herpesvirus scaffolding proteins are not found in infectious virions

True

Retroviruses only integrate into a few very sequence specific sites within the host cell genome.

True

Smallpox was named in 15th century France to distinguish it form large pox or syphilis.

True

The PrPSc protein is more resistant to proteases than the PrPC protein.

True

The interaction between the viral particle and the host cell receptor is a major determinant of the species specificity of viral infections.

True

The polymerase protein of hepB virus binds to the epsilon stem loop n the pregenomic mRNA, which is important for packaging of the genome into the capsid.

True

Describe two forms of early vaccination.

Variation involved taking scrapings from scabs of healing pox sores and inhaling them nasally. Another method involved subcutaneous scratching with an inoculated needle from the pus of an active pox sore.

During infection with poxviruses, all of the following proteins are produced from early genes except

Viral Early Transcription Factor

How do coronavirus enveloped virions get released from the host cell?

Virus containing vesicles fuse with the plasma membrane, releasing virions

It is recommended that people in certain professions or with certain diseases should receive the hepB vaccine. For which of the following individuals would it NOT be critical for the to be vaccinated?

Zoo keeper

The 5' end of the poliovirus genomic RNA contains all of the following except:

a 5' cap

All of the following features are associated with the incoming RNA genomes of retroviruses EXCEPT:

a single open reading frame.

Retroviruses use which of the following cellular molecules as the primer for genome replication?

a special transfer RNA

The Jelly Roll β barrel is:

a structure found in many viral capsid proteins

Entry of the poliovirus genome into the host cell does not involve:

acidification of the endosome

Genome segments 7 and 8 from influenza can produce two different proteins using which of the following mechanisms?

alternative mRNA splicing

A very common structure for bacteriophage particles is which of the following?

an icosahedral head with a helical tail

The 5' end of the poliovirus genomic RNA contains all of the following:

an unusually noncoding region, a pyrimidine-rich tract, a high degree of RNA secondary structure, and multiple AUG start codons

The word phage is a shortened version of the name of a virus that can infect which type of organism?

bacterial cell

Before the viral genome can be transcribed or replicated in a new host cell it must...

be uncoated in the appropriate compartment of the correct cell type.

Entry of the poliovirus genome into the host cell involves all of the following:

binding to a host cell receptor, extrusion of the hydrophobic N-terminus of VP1, conformational change of the virion, loss of the internalVP4 protein

West Nile Virus was introduced into the United States in 1999 and became an endemic infection over the next several years. Which of the following wild animal does this virus circulate in?

birds

Which of the following terms describes the protein shell that surrounds the viral genome?

capsid

Which of the following describes the primary mechanism of transmission of the flavivirus HepC?

contaminated blood transfusions

APOBEC3G

cytidine deaminase; C base pairs to U; HIV; vif

Which of the following is not a symptom of smallpox infection?

dementia

Which of the following describes the type of nucleic acids found in a reovirus genome?

dsRNA

The intergenic region on the SV40 chromosome contains DNA sequences that control which of the following processes?

early and late gene transcription, DNA replication

The Baltimore classification system describes the relationship between a viral genome and the...

early mRNAs

The lipid membrane that surrounds the nucleocapsid of some virus particles is called the...

envelope

The intergenic regions in the Ebola virus genome genome contain signals for all of the following processes EXCEPT...

genome replication

HIV....

gp41

Coronaviridae

helical, (+) stranded, non segmented RNA

Filoviridae

helical, (-) stranded, non segmented RNA

Rhabdoviridae

helical, (-) stranded, non segmented RNA

Orthomyxoviridae

helical, (-) stranded, segmented RNA

Buds into the perinuclear space

herpesvirus

Tetherin

holds virions to surface of cell (inhibiting vpu which releases); virions internalized and degraded

Most viruses that use a spherical shaped capsid arrange their capsid proteins with which of the following symmetries?

icosahedral

Togaviridae

icosahedral, (+) stranded, non segmented RNA

Which of the following statements about rabies is FALSE?

infection with the virus a 50% mortality rate in untreated individuals

Which of the following diseases is NOT caused by a member of the picornavirus family?

influenza

The SV40 middle T antigen can activate cell metabolism and the cell cycle by

interacting with the cellular c-Src protein

MxA proteins

interferes with transcription of influenza and other RNA viruses

The advantage of using a helical instead of an icosahedral nucleocapsid to package a ssRNA genome is...

it better protects the genome from degradation within the cell

Which of the following describes the function of dyein?

it is a motor protein that moves along the microtubules towards the nucleus

Which of the following describes the source of the protease that cleaves the picornavirus polyprotein into individual functional proteins?

it is a part of the polyprotein

What is unique about the RNAP encoded by the T7?

it is composed of a single polypeptide

Which component of the adenovirus virion binds to host cell receptors?

knob on the fiber protein and pentane base

Many large DNA viruses use which of the following components to get their nucleocapsid near to the host cell nucleus?

microtubules

Epstein-Barr virus causes

mononucleosis

If the genome of a negative-strand RNA virus, which has been purified away from all of the virion proteins, was injected into the cytoplasm of an appropriate host cell, what would happen first?

none of the above

Which of the following diseases is caused by a member of the picornavirus family?

none of the above

Polyomavirus...

packages genome as minichromosomes

Can cause head and neck cancers

papillomavirus

Early genes transcribed counterclockwise

papillomavirus

What cells produce antibodies?

plasma

Newley formed membrane structures become viral envelope

poxvirus

lateral bodies

poxvirus

Trim5alpha

prevents HIV in monkeys and SIV in humans

Which of the following describes the mechanism used to regulate the various functions of the RNA-dependent RNA polymerase from togaviruses?

proteolytic cleavage

Which of the following describes the major function of the proteins made from the alpha genes of herpes simplex virus?

regulation of viral gene expression

Genome is 10-12 linear segments

reovirus

sigma 1 protein

reovirus

Adenovirus...

replication involves panhandle formation of DNA strand

Herpes...

replication involves rolling circle

Poxvirus...

replication occurs only in host cell cytoplasm

What is another term for an RNA dependent DNAP?

reverse transcriptase

Which of the following describes the mechanism used by coronaviruses to produce the ORF1b?

ribosomal frameshifting

Variola virus causes

smallpox

Which of the following are NOT one of the most important criterion used to classify viruses into families?

species of host infected

What is a possible explanation for why ssDNA viruses have genomes less than 10kb in size?

ssDNA is not as physically stable as dsDNA

An interesting observation is that many highly pathogenic and deadly human viruses have the following type of genome:

ssRNA, negative sense

HIV...

tRNA is used for replication primer

Which part of the T7 virion binds to the lipopolysaccharide molecules on the OM of the host cell?

the tail fibers

What is interesting about the promoters that direct transcription of the Class II and Class III genes from bacteriophage T7?

they can only be recognized by viral RNAP

The role of flavivirus protein pr-M in the heterodimer or pr-M and E is...

to prevent the E protein from becoming fusion active in the low pH of the trans-Golgi

Depending on the type of virus, which of the following is function of the virus capsid?

to protect genome from nucleases and UV light, to attach to the correct type of cell and to ensure delivery of the genome into the host cell

The name of a virus family in the Latin classification system has which of the following endings?

viridae

Which of the following is the correct description for the term arboviruses?

viruses that all use an insect as a transmission vector