Quiz 1 Questions, Quiz 2, Quiz 3, Quiz 4, Quiz 5, Quiz 6, Quiz 7, Quiz 8, Quiz 9, Quiz 10, Quiz 11, Quiz 12, Quiz 13, Virology - Exam 1, Virology - Exam 2, Virology Exam 3, Virology Final

which statement about viral RNA genomes is correct

(+)ssRNA genomes may be translated to make viral protein

which of the following is the BEST definition of a virus

viruses are often ultra-microscopic obligate intra-cellular parasites which absolutely need a living cell of a host to replicate

viral receptors on the cell surface

-can be carb or protein molecules -interact with glycoproteins of enveloped viruses -can bind directly to icosahedral virus capsid proteins -have cell functions

Which of the following is the major difference between the Vesicular Stomatitis Virus (VSV) and influence virus mRNA synthesis? A. VSV mRNAs are synthesized in the cytoplasm whereas the influence virus mRNAs are synthesized in the nucleus B. VSV mRNA synthesis is carried out by viral RNA depdnet RNA polymerase; in contract, the influence virus steals/snatches the DNA dependent RNA polymerase from the nucleus of the host cell C. VSV produce unimolecular mRNAs whereas influence virus makes subgenomic mRNAs D. All of the above

A

how many viral genome types exist and which viral genome type was not included in the original "Baltimore Scheme" to make mRNA from different viral genomes

7 and gapped DNA virus

During SV40 DNA replication, the supercoiling of the dsDNA is inevitable. Which of the following statement correctly illustrates the different mechanisms of supercoiling removal during replication and after replication (terminal resolution)? A. During replication single strand nicks are responsible for supercoil relaxation whereas double stranded nicks are responsible for supercoil relocation (terminal resolution) at the end of DNA replication B. During replication both single and double strand nicks are responsible for supercoil relaxation whereas only double strand nicks are responsible for supercoil relaxation (terminal resolution) at the end of DNA replication C. During replication Topoisomerase II and after replication Topoisomerase I and II both carry out relaxation of the supercoils D. During replication Topoisomerase I and after replication Topoisomerase II carry out relaxation of the supercoils

A

How are the influenza virus and VSV RNA synthesis similar? A. all of the above B. the switch from mRNA to genome RNA synthesis is controlled by an RNA-binding protein C. Viral mRNAs are shorter than (-) genome RNA D. Polyadenylaation occurs at a short stretch of U residues

A

How is DNA replication of parvovirus and adenovirus similar? A. Replication occurs by strand displacement B. A replication fork forms at the origin of replication C. None of the above D. They both require protein-linked primers

A

The catalytic site of the RNA dependent RNA polymerase is present in which of the following domain? A. The Palm B. The Finger C. The knuckle D. The thumb

A

What is the first biosynthetic event that occurs in cells infected with dsDNA viruses? A. Transcription B. NA replication C. Membrane fusion D. Protein synthesis

A

Which is a part of the poliovirus replication strategy? A. Circularization of template for initiation of RNA synthesis B. All of the above C. De novo (without primer) initiation of RNA synthesis D. The production of subgenomic mRNAs

A

Which of the following is incorrect about the poxvirus DNA genome and its replication? A. all the viral replication proteins are synthesized by the virus B. The ends of the poxvirus DNA contain inverted terminal repeats (ITRs) C. Poxvirus DNA is a double stranded DNA with covalently joined ends D. Viral replication occurs in the cytoplasm of the cell

A

Which of the following is incorrect regarding Adenovirus DNA replication? A. A pre-terminal protein (pTP) binds to DNA poly and the a phosphoric group of a dGMP is bonded with a serine residue of the pTP; which acts as the primer for the DNA synthesis by bonding with the first dCMP on the template strand. B. The DNA is replicated by strand displacement C. DNA synthesis by strand displacement and DNA binding protein (DBP) coated displaced strand DNA synthesis both simultaneously participate in Adenovirus DNA replication D. The displaced strand during DNA synthesis is coated with a DNA binding protein and circularized where the inverted terminal repeats (ITRs) base pair and a new strand synthesis can initiate with the help of pre-terminal protein (pTP) using the 3' end as the template

A

Which of the following phases of transcriptional regulation is observed in Adenovirus? A. Immediate Early, Early, and Lat4e B. Early, Middle and Late C. Early, Late and very Late D. Early and Late

A

Which of the following process is involved in the regulation of viral DNA synthesis? A. all of the above processes are involved in the regulation of viral DNA synthesis B. Host replication proteins are induced by early viral gene products C. Viruses must recruit host replication proteins to preferentially synthesize viral DNA D. Virally encoded early gene products often induce quiescent cells to enter the cell cycle again into the S phase

A

Which of the following process occurs, immediately after the release of a viral gapped DNA or viral plus-stranded DNA? A. Repairment of dsDNA template for transcription B. Replication into dsRNA template for transcription C. Replication into double stranded genomic DNA D. Transcription into mRNA

A

Which of the following protein is produced in Simian Virus 40 (SV40) in the early phase of transcription and regulate DNA replication and expression of late genes? A. Large T antigen (LT) B. Small T antigen (ST) C. E2 D. E1A

A

Which protein is synthesized from the (+) strand RNA genome of the alpha virus (Togaviridae); immediately after the release of the genome RNA into a cell? A. The RNA dependent RNA polymerase B. The poly(A) binding protein PABP C. The poly(C) binding protein PCBP D. The membrane glycoprotein to form membrane vesicles for RNA synthesis

A

which of the following group of viruses usually pack RNA dependent RNA polymerase in the virus particle? A. Both A and C are correct B. Double stranded RNA viruses C. Minus strand RNA viruses D. Plus strand RNA viruses

A

Poxviruses and giant viruses never have to deliver their DNA into the nucleus. Which of the following would justify such a phenomenon? A. Pox and giant viruses have all the mRNAs packaged within the vision B. Pox and giant viruses have all the transcription machinery packaged within the virion C. Pox and giant viruses have all the translational machinery packaged within the virion D. Pox and giant viruses have all the DNA replication machinery packed within the virion

B

The mRNAs are synthesized by the Reovirus in which of the following structural state of the virus? A. Double capsid vision stage of the virus after in the acidic endosome B. When the core particle is released in the cytoplasm C. At the infectious Sub Viral Particle (ISVP) stage after acid-dependent proteolytic cleavage D. After the genomic RNAs are released into the cytoplasm from the core

B

The transcription of MOST but not all DNA viruses are carried out by which of the following enzyme? A. DNA pol III B. RNA pol II C. RNA pol III D. DNA pol I

B

Which is a universal rule about RNA directed RNA synthesis? A. RNA synthesis is always template-directed B. RdRp may initiate de novo or require a primer C. RNA synthesis initiates randomly on the RNA template D. RNA is synthesized in a 3'-5' direction

B

Which mode of transcriptional regulation is displayed; when transcription and translation of gene X result in the formation of protein X and protein X urn on the transcription of gene Y A. negative autoregulatory loop B. Cascade regulation C. positive feedback D. positive autoregulatory loop

B

Which of the following group of viruses usually do NOT pack RNA dependent RNA polymerase in the virus particle? A. Minus strand RNA viruses B. Plus strand RNA viruses C. All of the above pack RNA dependent RNA polymerase in the virus particle D. Double-Stranded RNA viruses

B

Which of the following is NOT a viral origin binding protein? A. Parvovirus Rep 78/68 protein B. Herpesvirus proliferative cell nuclear antigen (PCNA) protein C. Adenovirus pre-terminal protein (pTP) D. Polyomavirus (SV40) large T (LT) antigen protein

B

Which of the following is NOT true about mRNA polyadenylation of DNA viruses? A. The polyadenylation occurs in the nucleus before export into the cytoplasm B. PolyA polymerase slips on a few U residues to incorporate about 200 A residues at the 3' end of the RNA C. PolyA polymerase is the enzyme responsible for the polyadnelyation of the mRNAs D. The pre-mRNAs are cleaned at the prospective polyadenylation site for polyadenylation

B

Which of the following is true about the splicing of viral Pre-mRNAs? A. Some retroviral RNA is exported "unspoiled" out of the nucleus facilitated by special nuclear export binding proteins B. All of the above are true about viral mRNA splicing C. Alternative splicing can produce multiple proteins from the same Pre-mRNA D. Splicing is necessary for the binding and activation of the nuclear export proteins for most viral mRNA export into the cytoplasm from the nucleus

B

Which of the following mode of repression is seen in the late phase genes of Simian Virus 40 (SV40)? A. RNA pol II binding to an initiator sequence B. Initiator Binding Protein (IBP) binding to an initiator sequence C. Initiation complex binding to an initiator sequence D. TFIID binding to TATA sequence

B

Which of the following protein binds to the TATA sequence and regulate transcription? A. TFIIC B. TFIID C. TFIIB D. TFIIA

B

Which of the following protein/protein-complex is NOT associated with priming of DNA synthesis? A. Herpesvirus; UL5, 8 and 53-primase B. Parvovirus: Rep 78/68 protein C. Adenovirus: pre-terminal protein (pTP) D. SV40: DNA pol a-primase complex

B

Which of the following reaction takes place at the splicing site of a pre-mRNA? A. Acetylation B. Trans-esterification C. Methylation D. Cis-esterification

B

Which of the following type of metal ion coordinate the incoming nucleotide in a polymerization reaction catalyzed by polynucleotide polymerase class of enzymes like RNA or DNA polymerases? A. Tri-valent metal ion B. Di-valent metal ion C. Mono-valent metal ion D. Tetra-valent metal ion

B

Actinomycin D was utilized in the experiments that lead to the discovery of the viral RNA polymerase. What was the principle of the experiment? A. In the presence of dNTP and Actinomycin D; which inhibited cellular DNA dependent RNA polymerase; RNA synthesis occurred in the virally infected cell extract. B. In the presence of dNTP and Actinomycin D; which inhibited cellular DNA dependent RNA polymerase; RNA synthesis occurred in the virally infected cell extract C. In the presence of NTP and Actinomycin D; which inhibited cellular DNA dependent RNA polymerase; RNA synthesis occurred in the virally infected cell extract D. In the presence of NTP and Actinomycin D; which inhibited cellular RNA dependent RNA polymerase; RNA synthesis occurred in the virally infected cell extract

C

The SV40 genome is a circular dsDNA. which statement about its replication is correct? A. Viral large T (LT) antigen protein binds and unwinds the ori B. Replication is bidirectional from a single ori C. All of the above D, Has leading and lagging strand synthesis

C

The reverse transcriptase enzyme is coded by which region of a typical (e.g. Avian Leukosis Virus; ALV) retroviral genome? A. LTR B. env C. pol D. gag

C

What is the function of the cellular DNA ligase IV/XRCC4 in Herpesvirus DNA replication? A. DNA ligase IV/XRCC4 is responsible for end to end DNA ligation to form concatemers during rolling circle DNA synthesis B. DNA ligase IV/XRCC4 is responsible for the terminal resolution ligation of the separated DNA strands C. DNA ligase IV/XRCC4 is responsible for circularization of the viral DNA D. DNA ligase IV/XRCC4 is responsible sealing the gaps of the replicated DNA

C

Which of the following group of viruses ALWAYS contain an encapsidated RNA in the form of nucleocapsid? A. Double-stranded RNA viruses B. All of the RNA viruses have encapsidated RNA in the form of the nucleocapsid C. Minus strand RNA viruses D. Plus strand RNA viruses

C

Which of the following is NOT a character associated with cellular retinoblastoma (Rb) protein? A, Rb protein is a tumor suppressor gene B. Rb protein prevents the cells to enter into the S phase of the cell cycle C. Rb protein is an oncogene D. Loss of Rb protein is associated with childhood ocular malignant tumors

C

Which of the following is NOT a mechanism of viral DNA synthesis? A. Strand displacement DNA synthesis B. Rolling circle DNA synthesis C. All of the above D. Replication fork formation at the origin of replication for DNA synthesis

C

Which of the following is the correct function of the replication factor protein Rf-C? A. Rf-C binds to 3'-OH of the DNA, PCNA, and DNA pol b B. Rf-C acts as clamp loading protein to allow clamping of PCNA onto the DNA C. All of the above are correct functions of Rf-C D. Rf-C release DNA pol-a-primase complex

C

Which of the following is unique in Reovirus RNA dependent RNA synthesis? A. the RNA dependent RNA polymerase is located inside the viral core below the turret proteins which synthesize the mRNAs B. The mynas are produced inside the viral core particle and never synthesized in the cytoplasm C. All of the above are unique in Reovirus RNA dependent RNA synthesis D. One of each of the 10 segments of double-standee genomic RNA is associated with a viral RNA dependent RNA polymerase and is located under each "turret proteins" in each fivefold axis which synthesizes the mRNA

C

Which of the following process acts as the primary "switch" from Vesicular Stomatitis Virus (VSV) mRNA synthesis to genome RNA synthesis? A. slippage of the RNA polymerase at the 5' end of the genome RNA B. slippage of the RNA polymerase at the 3' end of the genome RNA C. Encapsidation of the "leader RNA" by N protein and association of N protein with RNA polymerase which reads through the intergeneric region D. Production of a large amount of viral structural proteins in the cell helps the RNA dependent RNA polymerase to read through the intergenic region

C

Which of the following process explains Adenoviral repression of transcription by Retinoblastoma (Rb) protein? A. Dp1 and E2F binds on the Adenoviral promoter. Then Rb protein binds to Dp1 and E2F and recruits histone deacetylases (Hdacs) which cause deacetylation of histones and loosen up the DNA around nucleosome inhibiting transcription B. E1A protein recruits Rb protein which causes deacetylation of histones and losses up the dNA around nucleosome inhibiting transcription C. Dp1 and E2F binds on the Adenoviral promoter. Then Rb protein binds to Dp1 and E2F and recruits histone deacetylases (Hdacs) which cause deacetylation of histones and wrapping DNA more tightly around nucleosome inhibiting transcription D. E1A protein recruits Rb protein which causes deacetylation of histones and wrapping DNA more tightly around nucleosome inhibiting transcription

C

How the "immediate early" transcriptional regulation of herpesvirus is different from the Adenovirus? A. Herpesvirus uses a cascade regulation unlike Adenoviral autoregulation B. Herpesvirus packs its RNA polymerase but Adenovirus do not C. The Herpesvirus "immediate early" transcription factor VP16 have cellular origin whereas adenovirus packs the "immediate early" E1A transcription factor in the virion D. The "immediate early" transcription factor VP16 is packaged into the Herpesvirus vision but Adenovirus use cellular transcription factors for its "immediate early" transcription

D

What makes poxvirus DNA replication different from all of the other viruses? A. The complete replication machinery is encoded by the viral genome B. DNA synthesis occurs in the nucleus C. DNA synthesis occurs by strand displacement D. None of the above

D

Which of the following acts as a primer for the initiation of poliovirus mRNA synthesis? A. the CRE element and covalently bonded two uridine residues B. The VPg protein C. The 3' pseudoknot D. The VPg protein and covalently bonded two uridine residues

D

Which of the following is NOT function of the large T (LT) antigen protein in SV40 DNA replication A. In presence of ATP, LT forms header and binds to the SV40 origin of replication and undergo conformational changes to denature the DNA strands B. LT protein in association with Rp-A, single stranded binding protein and Topoisomerase I shows helices activity and unwinds SV40 DNA C. Two LT protein hexameters ind on the opposite end of the SV40 origin of replication D. LT protein shows helices activity and unwinds the SV40 DNA in an ATP dependent manner

D

Which of the following is unique of a 5' cap structure of an mRNA? A. Usually, the first capping base is adenine B. The 2nd base guanine is methylated at the 2' OH of the ribose sugar C. The adenine is bonded to the second base guanine by a 5-5' phosphate linkage D. None of the above

D

Which of the following mechanism explains the abrogation of cellular Rb protein by viral proteins A. Viral protein like E1A binds to Rb protein and induce phosphorylation which dissociate Rb from E2f and Dp protein leading to transcriptional activation B. Viral proteins like E1A competitively binds to Rb protein; which in turn binds to transcription factor E2F and Dp to form E1A, Rb, E2F, Dp complex which induce transcription C. Viral protein like E1A binds to Rb and recruit histone deacetylases which lead to transcriptional activation D. Viral protein like E1A competitively binds to Rb protein which removes Rb protein bound to transcription factor E2f and Dp and Rb protein free E2f and Dp induce transcription

D

Which of the following process describes the polyadenylation of mRNAs in Vesicular Stomatitis Virus (VSV)? A. Snatching of poly (a) tails from cellular mRNAs B. All of the above processes can polyadenylate VSV mRNAs C. Addition of poly (a) with the help of Poly (A) binding protein, PABP D. Slippage of the RNA polymerase and recopying over a seven residue uridine (U7) at each intergenic region

D

Which of the following process form the 5' mRNA cap structure in the Influenza Virus? A. The 5' cap is cleaved and snatched by the virus from host small nuclear (sn) RNAs B. The RNA polymerase catalyzes a 7-methyl guanosine formation followed by 5'-5' triphosphate bridge formation to the second adenine base C. The RNA polymerase snatches a 5' binding protein cap to cap the mRNA and attach two uridine residues D. The 5' cap is cleaved and snatched by the virus from host nuclear pre-mRNAs

D

Which of the following process may be responsible for the regulation of viral transcription through nucleosomal templates? A. Histone de-acetylation B. Histone acetylation C. Histone methylation D. All of the above

D

Which of the following statement is true about Adenoviral transcriptional regulation? A. E2 produced in early phase enhance DNA replication B. DNA replication exhibit anti=repression by relief of promoter occlusion C. E1A produced in the immediate-early phase enhance early phase gene transcription D. All of the above are true

D

which of the following terms is used for a virus particle that can establish a plaque?

Plaque Forming Unit (PFU)

in the particle to pfu ratio particle can be described as

a virus which may or may not be infectious

which of the following enzyme is responsible for transcription of the viral RNA genome

RNA dependent RNA polymerase

flu virus fuses with the end-somali membrane by a low pH catalyzed fusion. which of the following process will trigger process

activation of the proton ATPases in the endosomal membrane

which of the following characteristics are associated with viral membrane (envelope) associated proteins?

all of the above

which of the following is the function of the structural proteins of a virus

all of the above

which of the following properties can be observed in the diverse RNA genome types of the viruses?

all of the above

why every virus particle does not form a plaque?

all of the above can be the cause of non-formation of plaques

which of the following reservoir do not harbor viruses? 1. atmosphere 2. soil, oceans, rivers and lake 3. all of the above harbor viruses 4. polar ice caps and snowy mountains 5. healthy living organism

all of the above harbor viruses

which of the following experimental method can be used in identification of a viral receptors

all of the above methods can be used inidenticiation of a viral receptor

which of the following defines a virion

an infectious virus particle

which of the following signature structure is used by the poliovirus to deliver its genomic RNA into a cell

an umbilicus protein connector

which of the following virus infects bacteria? 1. togavirus 2. bacteriophage 3. bacteroides 4. measles virus 5. yellow fever virus

bacteriophage

why is mRNA placed at the center of the baltimore scheme

because mRNA is made from all viral genomes

which of the following is true about the capsid but not the nucleocapsid

both of them can package DNA or RNA of any polarity fully enwrapped in proteins

which of the following is not a source of the viral envelope?

capsid or nucleocapsid

viral cytopathic effect can best be described as

cells showing pathological signs due to viral infection

which of the following does not play a role in virus entry

diffusion of virus particles in the cytoplasm

Which DNA genome, on entry into the cell, can be immediately copied into mRNA?

dsDNA

a "promoter" of a virus structure can be defined as...

it is the structural or asymmetric unit from which capsids or nucleocapsids are built

which of the following scientist established vaccination? 1. lady montagu 2. louis pasteur 3. robert Koch 4. anton van leeuwenhoek 5. edward jenner

edward jenner

what information may be encoded in a viral genome?

enzymes to replicate the viral genome

which of the following is NOT the function of the viral structural proteins

form structure that can prevent binding to host cell receptors

animal cell cultures, infected with certain viruses show the formation of syncytia. What best describes syncytial?

fusion of multiple cells to form giant cells

human gastrointestinal cells are resistant to cabbage looper baculovirus. which of the following best describes the statement?

human gastrointestinal cells do not have receptors for the cabbage looper baculovirus

a nucleocapsid inside an enveloped virus may have _________ symmetry

icosahedral or helical

which of the following is the definition of a subunit in a virus structure

it is a single folded polypeptide chain present in the viral structure

which of the following statements best describes an eclipse period of a virus growth cycle

its the period upon infection, when the virus is actively replicating its genome and forming the structural components of the virus inside the infected cells

which of the following were used to grow animal viruses before the development of growing animal viruses in cell culture

live animals and embryonate chicken eggs

which of the follow attributes the most in virus classification? 1. symmetry of the protein shell 2. presence or absence of a lipid membrane outside the capsid 3. nature and sequence of the nucleic acid 4. dimension of the virion and capsid 5. all of the above

nature and sequence of the nucleic acid

what type of stains are used in an electron microscope to visualize viruses? 1. hematoxylin and eosin 2. acidic stains 3. negative stain 4. positive stains 5. nigrosin

negative stains

which of the following describe virus symmetry and self-assembly

the bonding contacts of subunits are usually non-covalent

when a capsid contains more than 60 subunits, each occupies a _______ position

quasiequivalent

viral fusion peptides are exposed for insertion into the host cell membrane when

the endoscope becomes acidified

which of the following is true for a retrovirus

retrovirus contain reverse transcriptase which is carried by the virus inside the particle and can catalyze DNA intermediates from RNA immediately upon infection

a _______ and ______ cell is the only cell that can take up a virus particle and replicate it

susceptible and persmissive

which of the following is true about the fusion peptides used by the viruses

the are short hydrophobic peptides

which of the following is not a characteristic of a viral class I fusion protein

they are mostly beta sheets

which of the following isNOT a characteristic of a viral class II fusion protein

they are usually trimers

what was the principle/method that Martha and Chase used to discover that viral nucleic acid (DNA) is the genetic or hereditary molecule and not protein?

they labeled T4 bacteriophage proteins with radioactive sulfur and DNA with radioactive phosphorus and analyzed the progeny visions for the radioactivity in their proteins or DNA

which is a key concept first discovered about viruses that distinguished them from other microorganisms? 1. they could replicate only in broth 2. they were small enough to pass through a 0.2 micron filter 3. none of the above 4. they were too large to pass through a 0.2 micron filter 5. they made tobacco plants sick

they were small enough to pass through a 0.2 micron filter

the flu virus receptor is transmembrane protein-bound silica acid and it is linked to a terminal galatocse by either a(2,6) or a(2,3) bonding. which of the following viral property do you observe due to this change

this modulate the host specificity of the virus in between the human and avian strains

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 lysis of infected cells

which of the follow was the first virus discovered?

tobacco mosaic virus

production of the infectious virus after transformation of cells by viral DNA is called

transfection

which of the following statements is false? 1. viruses can only replicate in a living organism or host 2. viruses infect all different life forms on earth 3. viruses play a very important role in the biogeochemical cycle for sustainability 4. a viral infection may not cause a disease 5. viruses are ultra-microscopic and can be visualized only by electron microscopes

viruses are ultra-microscopic and can be visualized only by electron microscopes