virology final

Choose all correct statements about influenza viruses: 1. Major hosts for influenza viruses are waterfowl. 2. Type A influenza viruses cause severe respiratory disease in humans. 3. Amantidine is an antiviral drug that targets influenza virus HA protein. 4. The 3 subunits of the influenza virus replicase are PA, PB1 and PB2 5. The integral membrane ion channel protien is M2. Fusion with cells occurs at the plasma membrane.

1,2,4,5 3 is false. Amantidine inhibits M2 ion channel

Match the functions to the correct influenza virus protein (HA, NA, M1, M2): 1. attachment protein 2. fusion protein 3. cleaves sialic acid from glycoproteins 4. inhibited by amantadine

1. HA 2. HA 3. NA 4. M2

paramyxoviridae, rhabdoviridae, or both 1. Genomes are negative strand RNA and unsegmented 2. Virions have a distinct bullet shape 3. Measles and mumps viruses 4. Helical nucleocapsids 5. These viruses fuse with cells at the plasma membrane

1. Paramyxoviridae AND Rhabdoviridae 2. Rhabdoviridae 3. Paramyxoviridae 4. Paramyxoviridae AND rhabdoviridae 5. paramyxoviridae

Match the statement to the vaccine. Salk or Sabin. 1. This vaccine is given orally. 2. This vaccine generates an IgG response. 3. This is a killed/inactivated vaccine 4. This vaccine is no longer used in the United States. 5. This live attenuated vaccine contain 3 poliovirus serotypes. 6. The developer of this vaccine was awarded a Nobel Prize in Medicine

1. Sabin 2. Salk 3. Salk 4. Sabin 5. Sabin 6. Neither

Match the functions/statments with the correct cytoskeletal structures/protein. 1. cell shape 2. chromosome segregation 3. mechanical strength 4. hollow cylinders 5. Form the mitotic spindle that segregates chromosomes into daughter cells 6. Forms a dense, closslinked mesh directly under the cell plasma membrane

1. actin filaments 2. microtubules 3. intermediate filaments 4. microtubules 5. microtubules 6. actin filaments

type of immunity: 1. cytotoxic T lymphocytes are key players 2. production of neutralizing antibody

1. cell-mediated 2. humoral

Calculate the titer of a virus sample based on the following results of a plaque assay: Dilutions tested are 1/100, 1/1000, 1/10,000. 0.1 ml of each dilution is mixed with permissive cells and these are plated. The average number of plaques at each dilution is: 1/100 too many to count 1/1000 too many to count 1/10,000 ave= 300 plaques per plated sample.

3e7

The overall order of the three major retroviral genes is always

5' Gag-Pol-Env 3'

Transcription of retroviral RNA begins in what region of the LTR?

5' end of R

0.01 ml of a 1/10,000 dilution of virus is mixed with cells and plated, and the number of plaques is 57. What is the titer?

57 x 10 E 6 (57,000,000)

Acyclovir is very effective for control of which of the following viruses? A. Herpes simplex viruses B. Poxviruses C. Papillomaviruses D. Adenoviruses E. Vaccinia virus

A

Introduction of human papillomavirus DNA into transformed human cell lines does not result in the production of virus particles. Based on the normal life-cycle of papillomaviruses, which step is the virus life-cycle is most likely blocked in transformed cells? A. production of structural proteins B. synthesis of early proteins C. DNA replication D. transcription of early viral mRNAs E. exit from the cell

A

What enzyme synthesizes the RNA genome of a retrovirus? A. host cell RNA pol II B. host cell DNA pol I C. reverse transcriptase D. RNAse H E. rev

A

cleavage of parainfluenza virus F protein a. is performed by host cell proteases b. is not required for virus infectivity c. is performed by the viral NA protein d. F is not cleaved e. is performed by the viral PR protein

A

viral capsids are a. symmetrical structures assembled from virally encoded polypeptides b. Assembled from a few copies of very large capsid proteins. c. Assemble largely from host-encoded proteins. d. assembled from icosahedral polypeptides e. assembled from helical polypeptides

A

which of the following statements about picornavirus genome replication and gene expression are true: a. cleavage of a large viral polyprotein gives rise to all structural and nonstructural proteins b. two messenger RNAs are used for protein expression c. capsid proteins are encoded by a subgenomic mRNA d. A and B e. B and C

A

viruses are able to avoid immune recognition by down-regulating of MHC-class I proteins because a. MHC class 1 proteins bind and present antigens to the immune system (for example to T-cells) b. MHC class 1 proteins are the receptors for interferons c. MHC class 1 proteins are needed to activate interferon production d. MHC class 1 proteins bind and neutralize viruses before they infect cells e. MHC class 1 proteins are only expressed on virally infected cells

A (C was also accepted)

cells that have been treated with Type 1 interferons a. are in the antiviral state b. are more sensitive to viral infection c. become transformed d. A and B e. A, B, C

A *D was also accepted because there was a mistake in the notes, it's supposed to say more "resistant"

coronaviruses mRNA synthesis occurs by the general mechanism of __ and this leads to a high degree of __. a. discontinuous synthesis; RNA recombination b. frame shifting; reassortment c. discontinuous synthesis; point mutations d. cap snatching; antigenic drift e. stuttering' antigenic shift

A (but frame shifting does occur, so B is half right)

In the interferon-induced 2'-5'-oligo(A) pathway, mRNA is degraded by A. 2'-5'-oligo(A) synthase B. RNaseL C. interferon-α D. class II MHC E. DS RNA

B

Paramyxovirus viral mRNAs are synthesized very soon after the virus penetrates into the host cell. Which of the following must happen before the synthesis of viral genomes can begin? A. Synthesis of HA and F proteins B. Synthesis of N protein C. Host cell division D. Cleavage of F protein E. Synthesis of HA and F mRNAs

B

Persons with a high risk of developing nasopharyngeal carcinoma a. are of north american or european origin and have high antibodiy titers to Epstein-Barr virus b. are of asian origin and have high antibody titers to EBV c. are of asian origin and have decreasing titers to EBV d. have high antibody titers to EBV and are co-infected with malaria e. have low antibody titers to EBV and are co-infected with malaria

B

Retroviral protease A. cleaves the gag-pol polyprotein during assembly B. cleaves gag-pol polyprotein after assembly C. is expressed as part of the gag-pro or pro-pol polyproteins D. A and B are correct but not C E. B and C are correct but not A

B

Which characteristics are shared by ALL virus families in the Order Mononegavirales: A. Enveloped viruses with a 'bullet shape' B. Enveloped viruses with unsegmented, negative sense RNA genomes C. Non-enveloped viruses with negative sense RNA genomes D. Enveloped viruses with segmented genomes that replicate in the nucleus E. Enveloped viruses with icosahedral capsids.

B

an anti-HIV drug that binds to TM would most likely interfere with which step in the virus life cycle: a. binding/attachment b. fusion/entry c. reverse transcription d. integration e. transcription/mRNA processing

B

in HBV patients with chronic disease, non-infectious particles made up of what protein are present in large amounts in the blood? a. HBV C antigen b. HBV S antigen c. HBV E antigen d. HBV X protein e. HBV P protien

B

in order for papillomaviruses to complete their entire life cycle, what conditions must be met: a. infected cells must enter G0 phase b. infected cells must differentiate into keratinocytes c. virus must infect only the outermost layers of the skin (highly keratinized, highly differentiated epithelial cells) d. the viral genome must become integrated into the host cell genome e. infected basal cells must be killed

B

smallpox: A. emerged as a human disease about 20,000 years ago B. caused epidemics with up to 30% mortality C. was often an asymptomatic infection D. spread from the Americas to Europe and Asia E. All of the above are correct.

B

In order for papillomaviruses to complete their entire life cycle, which of the following conditions must be met? A. The viral genome must become integrated into the host cell genome. B. Infected cells must enter G0-phase. C. Infected cells must differentiate. D. Virus must infect only the outermost layers of the skin (highly keratinized, highly differentiated epithelial cells. E. The viral genome must be reverse transcribed.

C

Which of the listed viruses is a flavivirus A. Eastern equine encephalitis virus B. Western equine encephalitis virus C. West Nile Virus D. Rubella virus

C

an anti-HIV drug that could inhibit RNAseH activity would interfere with which step in the virus life cycle: a. binding/attachment b. fusion/entry c. reverse transcription d. integration e. transcription/mRNA processing

C

during infection of a cell with a positive strand RNA virus, which occurs first? a. synthesis of genomic RNA b. synthesis of anti-genomic RNA c. protein synthesis d. cleavage of host cell ribosomes e. the first product synthesized varies with the virus type

C

herpesvirus genomes are synthesized by a. a cellular DNA pol b. a cellular RNA pol c. a viral DNA pol d. a viral RNA pol e. a reverse transcriptase

C

interferons are a. antibodies b. the cell receptors for many viruses c. proteins d. A and B e. A, B, C

C

which of the following is/are true in regard to HIV transmission: a. transmission from recipient to donor sex partner is more frequent b. levels of virus in seminal fluid are always very low c. increased transmission occurs in presence of trauma or other STDs d. it has been demonstrated that antiretroviral therapy cannot decrease the risk of transmission e. all of the above are correct

C

Which statement about influenza virus HA protein is false? A. HA is the fusion protein B. HA is a target of neutralizing antibody C. HA0 is cleaved to HA1 and HA2 by neuraminidase D. HA is the attachment protein

C (cleaved by cellular proteases)

during infection of a cell with a positive strand RNA virus, which occurs first? a. synthesis of genomic RNA b. synthesis of anti-genomic RNA c. protein synthesis d. cleavage of host cell ribosomes e. the first product synthesized varies with the virus type

C. translation is always the first step for + strand RNA viruses.

All viruses share certain characteristics. Which statement is NOT true. a. Viral genomes are either DNA or RNA. b. All viruses are obligate intracellular parasites. c. Viruses are heterogeneous with respect to size, morphology, complexity, and host range. d. Some viruses can replicate (multiply) on the surface of an agar plate containing complex media. e. B and D are not true.

D

HIV protease inhibitors prevent which step in the replication of HIV-1? a. reverse transcription b. integration c. cleavage of envelope proteins d. maturation of the virus particle e. fusion

D

Papillomavirus E6 and E7 proteins A. are structural proteins B. inhibit host cell DNA synthesis C. are synthesized late after viral infection D. drive host cells into S phase E. are envelope proteins

D

Regarding paramyxoviruses: If host cells were treated with a drug to completely inhibit translation at the same time that virus was added to the culture, what viral products would be synthesized in the cells? A. viral capsids B. viral antigenomes C. viral genomes D. viral mRNAs E. viral proteins

D

The primary function of the cellular Rb gene product is: A. to bind to HPV E7 B. to bind to Adenovirus E1B C. to advance cells from G0 to the S phase of the cell cycle D. to control (inhibit) cell DNA replication E. to decrease transcription of genes responsible for DNA replication

D

Which of the following is an assay that can be used to enumerate transformed cells? A. growth on the surface of bacterial agar plates B. development of papillomas in all types of mice C. ability to be infected by papillomaviruses D. development of foci (miniature tumors) in monolayers E. growth in monolayers

D

a weak immune response to the Hep B virus usually results in a. chronic infection with severe liver damage b. clearance of virus c. death due to cytopathic properties of disease d. chronic infection with few symptoms e. A and c

D

ebola viruses A. Are filoviruses B. Are in the Order Mononegavirales C. Have an overall genome organization similar to the Orthomyxoviruses D. A and B are correct E. A, B, and C are correct

D

papillomaviruses: a. have a narrow host range b. are naked icosahedral particles c. have single stranded circular DNA genomes d. A and B e. A, B, C

D

when a viral protein is referred to as "structural," we are describing a protein that: a. is not found in the virion b. is not encoded by the viral genome c. is not synthesized in virus-infected cells d. is found in the virion e. does not have a function

D

which statements about the influenza virus M1 is/are correct? a. M1 is an ion channel b. M1 is not required for virus replication c. M1 is a nonstructural protein d. M1 is a structural protein e. M0 is cleaved to generate M1 and M2

D

Most infections with cytomegalovirus: A. cause tumors B. cause mononucleosis C. cause retinitis D. are asymptomatic E. A, B, and C are correct

D.

Adenovirus structural proteins: A. are late gene products B. are transcribed/translated after viral DNA replication C. are translated from a set of spliced mRNAs D. A and B are correct E. A, B and C are correct

E

Adenovirus structural proteins: a. are late gene products b. are transcribed after viral DNA replication c. are translated from a set of spliced mRNAs d. A and B e. A, B, C

E

HIV gp120 binds to CD4, which is found on what cells? a. helper T cells b. macrophages c. dendritic cells d. A and B e. A, B, C

E

adenovirus E1A and E1B proteins: a. are structural proteins b. are large envelope glycoproteins c. are capsid proteins d. inhibit virus maturation e. drive host cells into S phase

E

papillomaviruses A. have two envelope glycoproteins B. are easily grown in transformed cells C. are noted for their wide host range D. have linear DNA genomes E. are noted for causing benign tumors (cellular hyperplasia)

E

The function of the influenza virus NS2 protein is

Export of viral nucleocapsids from the nucleus

T/F Cap-snatching refers to removal of 5'methyl G caps from viral mRNAs

F

T/F Every virus infection leads to death of the infected cell.

F

T/F The 1918 pandemic influenza virus was call 'Spanish flu' because Spain was where the first outbreak occurred.

F

T/F The current H5N1 bird flu is easily transmitted among humans.

F

T/F Amantidine acts by inhibiting the M1 (matrix) protein

F

T/F Ongoing synthesis of influenza virus N protein in the infected cell is required for viral mRNA synthesis.

F

T/F Release of influenza virus nucleocapsid from the matrix protein requires increased pH in the interior of the virion.

F

T/F The stability of viral capsids is largely maintained by covalent interactions

F

T/F a virus that causes a lytic infection in cultured cells always causes disease in the host organism

F

T/F The function of poliovirus VPg is a primer for protein synthesis.

F (VPg is the replication primer)

t/f The major transmission route of Hepatitis C virus is fecal-oral

F (blood)

T/F The enteroviruses are a group of picornaviruses that cause epidemic gastroenteritis.

F (enteroviruses cause polio and rhinovirus- common cold)

The rabies virus protein that is responsible for attachment to host cells is called:

G protein

The 1918 pandemic flu virus was which type?

H1N1

Which hepatitis virus has animal reservoirs ?

Hep E

Jenner's smallpox vaccination was safer than the previously practiced variolation because

Jenner used cowpox lesions as the basis of his vaccine

Which paramyxovirus protein is the RNA replicase?

L protein

The antiviral drug Relenza targets which influenza virus protein.

NA

The cellular E2F protein binds to

Rb (retinoblastoma protein)

Influenza virus antigenic shift results from

Reassortment of genome segments

Which HIV protein mediates attachment?

SU

T/F Human and bird influenzaviruses usually bind to different versions of sialic acid.

T

T/F Intermediate filaments are comprised of keratins

T

T/F Kinesins are motor proteins that drive tranport of cargo along microtubules

T

T/F Picornavirus capsid assembly is a step-wise process.

T

T/F Positive strand RNA viruses often use proteolysis to generate individual viral proteins.

T

T/F The major transmission route of Hepatitis A virus is fecal-oral.

T

T/F The number and density of receptors on a cell will influence virus binding efficiency.

T

T/F When a virus particle attaches to a receptor it can continue moving along the plasma membrane

T

T/F Coronaviruses are large, compared to other plus strand RNA viruses (that we have studied in class)

T

T/F Dengue viruses are flaviviruses

T

T/F Hepatitis A virus is in the Genus Hepatovirus in the Family Picornaviridae.

T

T/F RNA-dependent RNA polymerases of the + strand RNA viruses are non-structural proteins

T

T/F Some Type A influenza viruses encode 11 proteins.

T

T/F The Noroviruses cause major outbreaks of gastroenteritis.

T

T/F Using a drug to inhibit host cell transcription will inhibit influenza virus replication.

T

t/F Rod shaped viruses have helical capsids.

T

T/F Fusion of viral envelopes with cellular plasma membranes occurs at neutral pH

T (but fusion within endosomes is at acidic pH)

T/F The cleavage of picornavirus VP23 to VP2 and VP3 is a maturation cleavage

T (quiz says F)

The capsids of togaviruses are arranged as what type of icosahedron? T=?

T=4

In the retrovirus LTR, what region contains the transcript promoter?

U3

In the retrovirus LTR, what region contains the transcription promoter ?

U3

hepatitis B virus is transmitted: a. via blood transfusion and bodily fluids b. via food and water c. from animals d. A and B e. A, B, C

a

the purpose of MHC proteins is to: a. bind and "present" peptides to immune cells b. act as receptor for interferons c. bind to carbohydrates d. inactivate viruses e. activate the interferon pathway

a

which of the following statements is true regarding the neutralizing antibody to HIV? a. levels of neutralizing antibody are relatively low and don't provide effective long-term control of virus replication b. levels of neutrlaizing antibody are relatively low but do provide effective long-term control of virus c. levels of neutralizing antibody are relatively high but don't provide effective long-term control of virus replication

a

DNA viruses: in which family is the viral genome linear dsDNA and uses a protein to prime DNA replication

adenovirus

Cells that have been treated with Type I interferons

are in the antiviral state are more sensitive to viral infection

Which characteristic is true of the Adenoviruses: A. viral structural proteins are synthesized before viral DNA is replicated B. naked particles with icosahedral symmetry C. viral DNA synthesis and packaging in the cytoplasm D. circular DNA genomes E. human adenoviruses cause cancer in humans

b

retroviral genomes are a. haploid b. diploid c. tetraploid d. segmented e. dsRNA

b

The purpose of MHC proteins is to

bind and 'present' peptides to immune cells

Diseases caused by human adenoviruses include a. T-cell and B-cell lymphomas b. rashes c. cold, pharyngitis, gastroenteritis or pneumonia d. hepatitis e. mononucleosis

c

Which of the following statements concerning "high risk" (for cervical cancer) human papillomaviruses is true? A. Infection by a high-risk HPV usually leads to the development of cervical cancer. B. They are the only HPV types that encode E6 and E7 proteins. C. They encode E6 and E7 proteins that have high binding affinity for p53 and Rb. D. They cause insertional activation of cellular oncogenes. E. Statements A, B and D are true.

c

the history of rabbit myxoma virus in Australia shows that: a. viruses cannot become stable when introduced into new populations b. a virus of moderate virulence cannot be maintained in a population c. viruses and their hosts can evolve, thereby changing the natural history of a viral infection d. highly virulent viruses can be used to eliminate rodent populations e. highly virulent viruses are stable and are easily maintained within a population

c

the internal ribosome entry sequence (IRES) a. is an RNA sequence that cleaves the ribosome b. is used for picornavirus genome replication c. is a viral RNA sequence that can be used to direct the assembly of ribosomes onto mRNA d. is a viral protein covalently linked to vial RNA e. is a viral sequence that inactivates host cell ribosomes

c

the result of most enterovirus infections is a. diarrhea/vomiting b. CNS disease c. inapparent infection d. hepatitis e. myocarditis

c

transcription of retroviral RNA begins in what region of the LTR? a. at the 5' end of U3 b. at the 5' end of U5 c. at the 5' end of R d. at the 5' end of Gag e. at the beginning of env

c

when activated, the 2'-5'-oligo(A) and PKR pathways inhibit a. penetration of virus b. virus uncoating c. translation of viral mRNA d. viral assembly e. all of the above

c

which statement is true a. an effective vaccine for dengue is widely used b. dengue virus can infect horses c. dengue is transmitted via a simple cycle that includes mosquitos and humans d. dengue is transmitted directly from one person to another via inhalation e. dengue is transmitted from horses to humans through mosquitos

c

norovirus family

calciviridae

SARS virus family

coronavirus

papillomaviruses: a. are noted for their wide host range b. are easily grown in transformed cells c. have two envelope glycoproteins d. are noted for causing benign tumors (cellular hyperplasia) e. have linear DNA genomes

d

the "eclipse phase" in the virus life cycle: a. is the same as the log phase of the bacterial growth curve b. is a period in the life cycle when no infectious virus particles can be measured c. is the extracellular phase of the virus life-cycle d. occurs after virus assembly e. is another way of saying 'virus attachment '

d

the primary function of the cellular Rb gene product is: a. to bind HPV E7 b. to bind to adenovirus E1B c. to bind to genes responsible for DNA replication d. to control cellular DNA replication e. A and B

d

the term virion specifically refers to a. the virus that is present during the eclipse phase of the viral life cycle b. all of the proteins encoded by the viral genome c. the nucleocapsid d. the extracellular virus particle e. none of the above

d

which cells have a half-life of years and "present" HIV to uninfected cells? a. macrophages b. activated CD4+ T cells c. quiescent CD4+ T cells d. dendritic cells e. neurons

d

for both retroviruses and hepadniviruses, the site of reverse transcription is in the: a. nucleus b. endoplasmic reticulum c. golgi d. extracellular virus particle e. cytoplasm

e

human papillomaviruses are grouped/classified: a. by tumor type b. using serologic assays to detect capsid proteins c. using serologic assays to detect envelope proteins d. by capsid structure e. based on genome sequence

e

the Fc receptors on macrophages bind to a. antigens b. interferons c. all viral envelope glycoproteins d. all viral capsid proteins e. antibodies

e

T/F The influenza virus mRNAs are used as templates for genome replication

f

T/F Coronaviruses have icosahdral capsids

f (helical)

Hep C virus belongs to what family

flaviviridae

dengue virus family

flaviviridae

hepatitis C virus family

flaviviridae

yellow fever virus belongs to what family

flaviviridae

yellow fever virus family

flaviviridae

DNA virus: in which family is the viral genome in the virion partially dsDNA?

hepadnaviridae

Hepatitis E viruses are members of which virus family

hepeviridae

What enzyme synthesizes the RNA genome of a retrovirus?

host cell RNA pol

what enzyme synthesizes the RNA genome of a retrovirus

host cell RNA pol II

Nipah, Hendra, Rabies and Ebola viruses:

infect bats

in order to cause paralytic polio, poliovirus must replicate in the

intestine

The genomes of Adenoviruses are:

linear dsDNA

T/F Coronavirus subgenomic mRNAs are generated by splicing

notes say T, quiz says F.

HIV Protease (PR) inhibitors interfere with which step in the virus life cycle:

particle maturation

list the + strand RNA viruses

picorna calci hepE flavi toga corona

unenveloped icosahedral viruses: picornaviridae togaviridae coronaviridae flaviviridae calciviridae

picorna and calci

hep A virus belongs to what family

picornaviridae

hepatitis A virus family

picornaviridae

The organization of flavivirus genomes is most similar to

picornaviruses

Infectious virus particles can counted by

plaque assays

DNA viruses: which family replicates in hte cytoplasm

poxviridae

Choose all response that CORRECTLY describes members of the Family Orthomyxoviridae. 1. Unsegmented genomes 2. Order Mononegavirales 3. Attachment and fusion both mediated by the HA protein. 4. Replication is nuclear 5. Answers 2, 3, and 4 are correct. 6. Answers 3 and 4 are correct

quiz says 6, but it should be 5. It IS in order mononegavirales!

Persons with a high risk of developing Burkitt's lymphoma: A. are African children infected with malaria and Epstein-Barr virus B. are Asian children with high antibody titers to Epstein-Barr virus C. are adults of Asian origin with high antibody titers to Epstin-Barr virus D. are Asian children with low antibody titers to Epstein-Barr virus E. are African children with malaria and cytomegalovirus infection

quiz says B but notes imply A because malaria is a cofactor

Vaccines for hepatitis B are made from

recombinant S protein

DNA viruses: in which family is integration of the viral genome required for replication

retroviridae

DNA viruses: in which family does the viral genome in the virion consist of two identical copies of RNA?

retroviruses

list the - strand RNA viruses

rhabdo paramyxo filo orthomyxo

Epstein-Barr virus is primarily transmitted via

saliva

The retroviral envelope proteins are synthesized from

single spliced mRNAs

Antigenic drift in influenza viruses is the result of

the accumulation of point mutations

a PCR assay for enumerating a virus detects

the virus sequence

Endogenous retroviruses are transmitted

through the germ line

rubella virus belongs to what fmaily

togaviridae

rubella virus family

togaviridae

The genome arrangement of the caliciviruses is the most similar to which other plus strand RNA virus?

togaviruses

When activated, the 2'-5'-oligo(A) and PKR pathways inhibit

translation of viral mRNA

he most common human disease resulting from Adenovirus infection is

upper respiratory infections (stressful conditions worsen)

Hepatitis B virus is transmitted

via blood and other bodily fluids

The history of rabbit myxoma virus in Australia shows that:

viruses and their hosts can evolve, thereby changing the natural history of a viral infection