Virology Exam 2
How many di-valent metal ion binding sites are present in reverse transcriptase holoenzyme? a. 4 b. 3 c. 1 d. 2
a. 4
The SV40 genome is a circular dsDNA. Which statement about its replication is correct? a. All of the above b. Has leading and lagging strand synthesis c. Viral Large T (LT) antigen protein binds and unwinds the ori d. Replication is bidirectional from a single ori
a. All of the above
Which of the following process may be responsible for the regulation of viral transcription through nucleosomal templates? a. All of the choices are correct b. Histone methylation c. Histone de-acetylation d. Histone acetylation
a. All of the choices are correct
Which of the following is the correct function of the replication factor protein Rf-C? a. All of the mentioned functions of Rf-C are correct b. Rf-C acts as a clamp loading protein to allow clamping of Pcna onto the DNA c. Rf-C binds to 3′-OH of the DNA, Pcna and DNA pol δ d. Rf-C release DNA pol α-primase complex
a. All of the mentioned functions of Rf-C are correct
Which of the following strategy is observed in the Coronavirus reproductive events? a. All of the other events are observed in the Coronavirus reproductive cycle b. The genomic RNA is synthesized on a (−) sense template where the viral RdRp do not jump from any of the translational regulatory sequences (TRS) making the long (+) sense genomic RNA without any loss of nucleotides c. mRNAs are synthesized on (−) sense templates that use a 3′co-priming followed by a variable-length nested RNA synthesis and addition of the 5′leader sequence d. Two long polyproteins are translated by the ribosome by ribosomal frame shifting
a. All of the other events are observed in the Coronavirus reproductive cycle
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. Viral replication occurs in the cytoplasm of the cell c. The ends of the poxvirus DNA contain inverted terminal repeats (ITRs) d. Poxvirus DNA is a double stranded DNA with covalently joined ends
a. All the viral replication proteins are synthesized by the virus
Which of the following is NOT a viral origin binding protein? a. Herpesvirus proliferative cell nuclear antigen (Pcna) protein b. Adenovirus pre-terminal protein (pTP) d. Polyomavirus (SV40) Large T (LT) antigen protein d. Parvovirus Rep 78/68 protein
a. Herpesvirus proliferative cell nuclear antigen (Pcna) protein
Which of the following mode of repression is seen in the late phase genes of Simian Virus 40 (SV40)? a. Initiator Binding Protein (IBP) binding to an initiator sequence b. Initiation complex binding to an initiator sequence c. TFIID binding to TATA sequence d. RNA pol II binding to an initiator sequence
a. Initiator Binding Protein (IBP) binding to an initiator sequence
"Endogenization" is a term used to define which of the following statement? a. Integration of the proviral DNA in host germline and passage onto the next progeny b. Excision of the proviral DNA from the host germ cell DNA and passage onto the autosomes c. Movement and reintegration of proviral and retrotransposons in host by reverse transcriptase d. Integration of the proviral DNA into the host chromosomes
a. Integration of the proviral DNA in host germline and passage onto the next progeny
Which statement about viral DNA synthesis is correct? a. Large DNA viruses encode many proteins involved in DNA synthesis b. Small DNA viruses do not encode any protein involved in DNA synthesis c. Some viruses encode all proteins needed for DNA replication d. Viral DNA replication begins as soon as the genomic DNA is delivered into the nucleus
a. Large DNA viruses encode many proteins involved in DNA synthesis
What strategy is used by the Poliovirus to make many proteins from a single mRNA? a. Proteolytic cleavage of the polyprotein b. Alternative translational stop c. Alternative splicing d. Alternative translational start
a. Proteolytic cleavage of the polyprotein
Which is a universal rule about RNA directed RNA synthesis? a. RdRp may initiate de novo or require a primer b. RNA synthesis initiates randomly on the RNA template c. RNA is synthesized in a 3'-5' direction d. RNA synthesis is always template-directed
a. RdRp may initiate de novo or require a primer
Which of the following is NOT a universal rule of viral DNA replication? a. Replication can initiate at random sites on templates called origin of replication b. DNA synthesis may be primer dependent or independent c. The dNTPs are incorporated at the 3′-OH of the DNA chain d. The DNA synthesis is always template directed
a. Replication can initiate at random sites on templates called origin of replication
Which of the following process describes the polyadenylation of mRNAs in Vesicular Stomatitis Virus (VSV)? a. Slippage of the RNA polymerase and recopying over a seven residue uridine (U7) at each intergenic region b. Addition of poly(A) with the help of Poly(A) binding protein, PABP c. All of the above processes can polyadenylate VSV mRNAs d. Snatching of poly(A) tails from cellular mRNAs
a. Slippage of the RNA polymerase and recopying over a seven residue uridine (U7) at each intergenic region
Which of the following sequence is the part of the "core promoter" sequence for RNA polymerase II? a. TATA sequence b. Trans-acting local regulatory sequences d. Cis-acting local regulatory sequences e. All of the choices constitute the "core promoter"
a. TATA sequence
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 nuclear pre-mRNAs b. The 5`cap is cleaved and snatched by the virus from host small nuclear (sn) RNAs c. The RNA polymerase catalyzes a 7-methyl guanosine formation followed by 5`-5` triphosphate bridge formation to the second adenine base d. The RNA polymerase snatches a 5` binding protein cap to cap the mRNA and attach two uridine residues
a. The 5`cap is cleaved and snatched by the virus from host nuclear pre-mRNAs
Which of the following is NOT true about the Long Terminal Repeat (LTR) in a retrovirus; such as HIV-1? a. The LTRs are found on both the 5` and 3` end of the diploid retroviral genome (+) RNA genome b. The LTRs have strong promoters c. The LTRs are essential for integration into the host genome d. The LTRs have signature U3, R and U5 regions flanked by pbs (primer binding site) and ppt (poly purine tract)
a. The LTRs are found on both the 5` and 3` end of the diploid retroviral genome (+) RNA genome
The catalytic site of the RNA dependent RNA polymerase is present in which of the following domain? a. The Palm b. The knuckle c. The Thumb d. The Finger
a. The Palm
Which of the following statement is NOT correct about a typical (e.g. Avian Leukosis Virus: ALV) retrovirus? a. The unspliced env pre-mRNA codes SU (surface) and TM (transmembrane) proteins b. The one strand of genomic RNA, Gag-pol-env mRNA and the unspliced pre-mRNA are the all the same c. All of the other statements are correct about the typical (e.g. Avian Leukosis Virus: ALV) retrovirus d. Protease processing/cleaving of the Gag precursor protein forms several viral proteins e. The pol region of the retroviral genome code for reverse transcriptase and integrase
a. The unspliced env pre-mRNA codes SU (surface) and TM (transmembrane) proteins
What is the first biosynthetic event that occurs in cells infected with dsDNA Viruses? a. Transcription b. Membrane fusion c. NA replication d. Protein synthesis
a. Transcription
Which of the following mechanism explains the abrogation of cellular Rb protein by viral proteins a. 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 b. Viral protein like E1A binds to Rb protein and induce phosphorylation which dissociate Rb from E2f and Dp protein leading to transcriptional activation c. 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 d. Viral protein like E1A binds to Rb and recruit histone deacetylases which lead to transcriptional activation
a. 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
Which of the following is true about the splicing of viral Pre-mRNAs? a. 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. All of the above are true about viral mRNA splicing c. Some retroviral RNA is exported "unspliced" out of the nucleus facilitated by special nuclear export binding proteins d. Alternative splicing can produce multiple proteins from the same Pre-mRNA
b. All of the above are true about viral mRNA splicing
Which of the following steps occur during reverse transcription of retroviral genomic RNA? a. Degradation of the viral RNA by RNase H b. All of the mentioned events occur during reverse transcription c. Generation of two LTRs d. Priming of (−) DNA synthesis by tRNA e. Two template exchanges
b. All of the mentioned events occur during reverse transcription
Which of the following process is involved in the regulation of viral DNA synthesis? a. Virally encoded early gene products often induce quiescent cells to enter the cell cycle again into the synthesis (S) phase b. All of the mentioned processes are involved in the regulation of viral DNA synthesis c. Viruses must recruit host replication proteins to preferentially synthesize viral DNA d. Host replication proteins are induced by early viral gene products
b. All of the mentioned processes are involved in the regulation of viral DNA synthesis
Adenovirus E1A protein stimulating the expression of adenovirus E2 protein which then stimulates the expression of adenovirus IVa2 & L4 protein is an example of: a. Repression of gene expression b. Cascade regulation c. Dimerization d. A negative autoregulatory loop
b. Cascade regulation
Which mode of transcriptional regulation is displayed; when transcription and translation of gene X result in the formation of protein X and protein X turn on the transcription of gene Y. a. Positive feedback b. Cascade regulation c. Positive autoregulatory loop d. Negative autoregulatory loop
b. Cascade regulation
Which of the following process explains Adenoviral anti-repression of transcription by abrogation of Rb (Retinoblastoma protein)? a. E2fbinds to Rb and prevents Rb Retinoblastoma protein) to be associated with E1A and Dp-1. In absence of Rb, no Hdacs (histone deacetylases) are recruited making the DNA loose and accessible around the nucleosome, and transcription complex can be formed and proceed. b. E1A binds to Rb and prevents Rb Retinoblastoma protein) to be associated with E2F and Dp-1. In absence of Rb, no Hdacs (histone deacetylases) are recruited making the DNA loose and accessible around the nucleosome, and transcription complex can be formed and proceed. c. E2f binds to Rb and prevents Rb (Retinoblastoma protein) to be associated with E2F and Dp-1. In absence of Rb, no Hdacs (histone deacetylases) are recruited making the DNA loose and accessible around the nucleosome, and transcription complex can be formed and proceed. d. E1A binds to Rb and prevents Rb Retinoblastoma protein) to be associated with E2F and Dp-1. In absence of Rb, no Hdacs (histone deacetylases) are recruited making the DNA tightly wrapped around the nucleosome, and transcription complex can be formed and proceed.
b. E1A binds to Rb and prevents Rb (Retinoblastoma protein) to be associated with E2F and Dp-1. In absence of Rb, no Hdacs (histone deacetylases) are recruited making the DNA loose and accessible around the nucleosome, and transcription complex can be formed and proceed.
Which of the following region is the actual start site for mRNA transcription? a. Repressor sequence b. Initiator sequence c. Enhancer sequence d. TATA sequence
b. Initiator sequence
Which of the following define the most logical function of reverse transcriptase in most cases (ignoring the few exceptions)? a. It is an RNA dependent RNA polymerase b. It is an RNA dependent DNA polymerase c. It is a DNA dependent RNA polymerase d. It is a DNA dependent DNA polymerase
b. It is an RNA dependent DNA polymerase
Which of the following group of viruses ALWAYS contain an encapsidated RNA in the form of nucleocapsid? a. All of the RNA viruses have encapsidated RNA in the form of the nucleocapsid b. Minus strand RNA viruses c. Double-stranded RNA viruses d. Plus strand RNA viruses
b. Minus strand RNA viruses
Which of the following is NOT true about mRNA polyadenylation of DNA viruses? a. PolyA polymerase is the enzyme responsible for the polyadenylation of the mRNAs b. PolyA polymerase slips on a few U residues to incorporate about 200 A residues at the 3` end of the RNA c. The polyadenylation occurs in the nucleus before export into the cytoplasm d. The pre-mRNAs are cleaved at the prospective polyadenylation site for polyadenylation
b. PolyA polymerase slips on a few U residues to incorporate about 200 A residues at the 3` end of the RNA
Which of the following is true about Hepadnavirus? a. The 5` end of the (-) strand DNA is attached to an RNA primer for reverse transcription b. Reverse transcription happens only in the core particle with partially assembled capsid c. The viral reverse transcriptase is attached to the 5′ end of the (+) strand and immediately reverse transcribe the genome upon entry into the cytoplasm d. All of the other statements are true about Hepadnavirus e. They contain circular DNA as their genome where one strand is complete, circular and covalently closed and the other strand is only about 2/3 complete
b. Reverse transcription happens only in the core particle with partially assembled capsid
Which of the following is true about Hepadnavirus? a. The viral reverse transcriptase is attached to the 5′ end of the (+) strand and immediately reverse transcribe the genome upon entry into the cytoplasm b. Reverse transcription happens only in the core particle with partially assembled capsid c. The 5` end of the (-) strand DNA is attached to an RNA primer for reverse transcription d. They contain circular DNA as their genome where one strand is complete, circular and covalently closed and the other strand is only about 2/3 complete e. All of the other statements are true about Hepadnavirus
b. Reverse transcription happens only in the core particle with partially assembled capsid
Spliceosomes which of the following is found in a spliceosome? a. Ribosomal RNAs b. Small nuclear RNAs (snRNA) c. Micro RNAs (mi-RNA) d. Silencing RNAs (siRNA)
b. Small nuclear RNAs (snRNA)
Which statement about viral DNA synthesis is NOT correct? a. Small DNA viruses encode at least one protein involved in DNA synthesis b. Some viruses encode all proteins needed for DNA replication c. Viral DNA replication is always delayed after infection because it requires the synthesis of at least one viral protein d. Large DNA viruses encode many proteins involved in DNA synthesis
b. Some viruses encode all proteins needed for DNA replication
Which RNA polymerase mode of action "model" explains the VSV mRNA synthesis and attenuation at intergenic regions? a. Moving template model b. Stop-start model c. Protein dependent priming model d. Cap snatching model
b. Stop-start model
Which of the following non-retro-viral DNA replication does not require an RNA primer? a. Replication fork based DNA synthesis from a multiple origins b. Strand displacement DNA synthesis c. Replication fork based DNA synthesis from a single origin d. Rolling circle DNA synthesis
b. Strand displacement DNA synthesis
Which of the following protein binds to the TATA sequence and regulate transcription a. TFIIA b. TFIID c. TFIIC d. TFIIB
b. TFIID
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 and covalently bonded two uridine residues c. The 3` pseudoknot d. The VPg protein
b. The VPg protein and covalently bonded two uridine residues
Coronavirus and Retrovirus are two unique viruses among the plus-strand RNA viruses. Which of the following feature make them unique? a. Both A and B are correct b. They are the only plus-strand RNA viruses with encapsidated genomic RNA in the form of the nucleocapsid c. They are the only enveloped viruses among plus-strand RNA viruses d. Both of them carry reverse transcriptase
b. They are the only plus-strand RNA viruses with encapsidated genomic RNA in the form of the nucleocapsid
The mRNAs are synthesized by the Reovirus in which of the following structural state of the virus? a, Double capsid virion stage of the virus after in the acidic endosome b. When the core particle is released into the cytoplasm c. After the genomic RNAs are released into the cytoplasm from the core d. At the Infectious Sub Viral Particle (ISVP) stage after acid-dependent proteolytic cleavage
b. When the core particle is released into the cytoplasm
Which of the following process facilitates the second template exchange of hepadnavirus reverse transcription? a. RNase H digestion of the 3′ dr1 sequence and downstream secondary structure facilitates template switching in the pre-genomic RNA b. Template switching is initiated by the 5′ end limit product of the RNaseH digestion of the pre-genomic RNA c. A hairpin formation near the 3′ end of the DR1 sequence on the (−) strand DNA switches the RNA primer to the DR2 sequence near the 5′ end of the (−) strand DNA d. Conformational change of TP (terminal protein) and reverse transcriptase exchange the template from 5′ end to 3′end of the pre-genomic RNA
c. A hairpin formation near the 3′ end of the DR1 sequence on the (−) strand DNA switches the RNA primer to the DR2 sequence near the 5′ end of the (−) strand DNA
Which of the following is incorrect regarding Adenovirus DNA replication? a. DNA synthesis by strand displacement and DNA binding protein (DBP) coated displaced strand DNA synthesis both simultaneously participate in Adenovirus DNA replication b. The DNA is replicated by strand displacement c. A pre-terminal protein (pTP) binds to DNA pol and the α phosphoryl 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 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
c. A pre-terminal protein (pTP) binds to DNA pol and the α phosphoryl 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
Which of the following enzyme/s has/have conserved GDD (or significantly close) amino acid motifs at their catalytic site? a. DNA dependent DNA polymerase b. RNA dependent RNA polymerase c. All of the above enzymes have conserved GDD (or significantly close) amino acid motifs d. DNA dependent RNA polymerase e. RNA dependent DNA polymerase
c. All of the above enzymes have conserved GDD (or significantly close) amino acid motifs
What is the function of the cellular DNA ligase IV/XRCC4 in Herpesvirus DNA replication? a. DNA ligase IV/XRCC4 is responsible sealing the gaps of the replicated DNA 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 for end to end DNA ligation to form concatemers during rolling circle DNA synthesis
c. DNA ligase IV/XRCC4 is responsible for circularization of the viral DNA
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 Topoisomerase II and after replication Topoisomerase I and II both carry out relaxation of the supercoils b. During replication Topoisomerase I and after replication Topoisomerase II carry out relaxation of the supercoils c. During replication single strand nicks are responsible for supercoil relaxation whereas double strand nicks are responsible for supercoil relaxation (terminal resolution) at the end of DNA replication d. 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 single strand nicks are responsible for supercoil relaxation whereas double strand nicks are responsible for supercoil relaxation (terminal resolution) at the end of DNA replication
Which of the following protein/protein-complex is NOT associated with priming of DNA synthesis? a. Herpesvirus: UL5, 8 and 53-primase b. SV40: DNA pol α - primase complex c. Parvovirus: Rep78/68 protein d. Adenovirus: pre-terminal protein (pTP)
c. Parvovirus: Rep78/68 protein
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. All of the above pack RNA dependent RNA polymerase in the virus particle c. Plus strand RNA viruses d. Double-stranded RNA viruses
c. Plus strand RNA viruses
The transcription of MOST but not all DNA viruses are carried out by which of the following enzyme? a. DNA pol I b. DNA pol III c. RNA pol II d. RNA pol III
c. RNA pol II
How is DNA replication of parvovirus and adenovirus similar? a. They both require protein-linked primers b. None of the above c. Replication occurs by strand displacement d. A replication fork forms at the origin of replication
c. Replication occurs by strand displacement
Which of the following statements about retroelements is NOT correct? a. There are many retroelement copies in eukaryotic genomes b. None of the above/other c. Retroelements in the human genome sometimes may be fully transcribed to produce infectious viruses d. They can be beneficial e. They are currently entering the Koala germline in south-eastern Australia
c. Retroelements in the human genome sometimes may be fully transcribed to produce infectious viruses
Which of the following is NOT true about a typical (e.g. Avian Leukosis Virus: ALV) retrovirus genome and its function? a. Host tRNAs are packaged in the virion bound to the pbs (primer binding site) of the genome b. The retroviral genome is (+) strand RNA with two identical copies in each virion c. The (+) strand genome RNA is 5′ capped and 3′ polyadenylated and immediately translated into Gag and Gag-Pol polyprotein precursor immediately upon viral entry into the host cell d. The viral genome is coated with nucleocapsid protein
c. The (+) strand genome RNA is 5′ capped and 3′ polyadenylated and immediately translated into Gag and Gag-Pol polyprotein precursor immediately upon viral entry into the host cell
Which of the following feature is NOT observed in DNA dependent DNA polymerases? a. They contain the thumb, palm and the finger domain d. Have conserved GDD or close amino acid motifs at the catalytic site c. The thumb domain act as the catalytic site d. Di-valent metal ions coordinate the incoming nucleotide to catalyze the reaction
c. The thumb domain act as the catalytic site
Which of the following statement is NOT correct about a typical (e.g. Avian Leukosis Virus: ALV) retrovirus? a. All of the other statements are correct about the typical (e.g. Avian Leukosis Virus: ALV) retrovirus b. The one strand of genomic RNA, Gag-pol-env mRNA and the unspliced pre-mRNA are the all the same c. The unspliced env pre-mRNA codes SU (surface) and TM (transmembrane) proteins d. Protease processing/cleaving of the Gag precursor protein forms several viral proteins e. The pol region of the retroviral genome code for reverse transcriptase and integrase
c. The unspliced env pre-mRNA codes SU (surface) and TM (transmembrane) proteins
Which of the following reaction takes place at the splicing site of a pre-mRNA? a. Cis-esterification b. Acetylation c. Trans-esterification d. Methylation
c. Trans-esterification
Which of the following is incorrect about the poxvirus DNA genome and its replication a. Poxvirus DNA is a double stranded DNA with covalently joined ends b. The ends of the poxvirus DNA contain inverted terminal repeats (ITRs) c. Viral replication occurs in the cytoplasm of the cell d. All the viral replication proteins are synthesized by the virus
d. All the viral replication proteins are synthesized by the virus
Which of the following is the most logical explanation behind the naming "reverse transcriptase" a. Because of the enzyme's ability to reverse the process of translation followed by transcription b. All of the other statements are correct logics behind the naming c. Because of the enzyme's ability to synthesize the RNA from the DNA in a reverse order using 5′ end of the RNA as the initiation site d. Because of the enzyme's ability to reverse the flow of the genetic information
d. Because of the enzyme's ability to reverse the flow of the genetic information
DNA viruses require DNA binding proteins for transcriptional control. Which of the following may be the source of these DNA binding proteins? a. Only the virus b. None of the choices are correct c. Only the host cell d. Both virus and/or the host cell
d. Both virus and/or the host cell
Which is a part of the Poliovirus replication strategy? a. All of the above b. The production of subgenomic mRNAs c. De novo (without primer) initiation of RNA synthesis d. Circularization of template for initiation of RNA synthesis
d. Circularization of template for initiation of RNA synthesis
Which of the following might be the most probable cause of resistance of retroviruses against UV and ionizing radiation? a. Retroviruses use cellular RNA pol II to make mRNAs and proteins from the integrated provirus; which is resistant to UV and ionizing radiation b. As the provirus is integrated in the host genome UV and ionizing radiation does not have any effect on the retroviruses c. Reverse transcription is error prone and likely repair the mutation caused by UV and ionizing radiation; a mechanism not seen in any other viruses d. Copy choice in between two RNA copies of the diploid genome is likely to build an error free functional genome; even if one of the gene is mutated due to UV and ionizing radiation
d. Copy choice in between two RNA copies of the diploid genome is likely to build an error free functional genome; even if one of the gene is mutated due to UV and ionizing radiation
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. Mono-valent metal ion c. Tetra-valent metal ion d. Di-valent metal ion
d. Di-valent metal ion
Which of the following phases of transcriptional regulation is observed in Adenovirus? a. Early, Middle and Late b. Early and Late c. Early, Late and Very late d. Immediate Early, Early, and Late
d. Immediate Early, Early, and Late
Which statement about polyadenylation of DNA virus mRNAs is correct? a. It always occurs in the cytoplasm b. Poly(A) is added at the 5'-end of pre-mRNA c. Is specified by a stretch of U residues in the template d. It occurs after cleavage of pre-mRNA
d. It occurs after cleavage of pre-mRNA
Which of the following group of viruses does NOT have naked RNA in the virus particle? a. Plus strand RNA viruses b. Double-stranded RNA viruses c. None of the group of viruses above has naked RNA in the virus particle d. Minus strand RNA viruses
d. Minus strand RNA viruses
Which of the following method is used by the Influenza virus to synthesize its mRNAs? a. Stop start model b. 3′co-priming and nested mRNA synthesis model c. In-particle mRNA synthesis model d. Moving template model
d. Moving template model
Which of the following is unique of a 5′ cap structure of an mRNA? a. The adenine is bonded to the second base guanine by a 5-5` phosphate linkage b. Usually, the first capping base is adenine c. The 2nd base of the cap is guanine, which is methylated at the 7th carbon (m7) d. None of the choices are correct
d. None of the choices are correct
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. Loss of Rb protein is associated with childhood ocular malignant tumors d. Rb protein is an oncogene
d. Rb protein is an oncogene
How the "immediate early" transcriptional regulation of Herpesvirus is different from the Adenovirus? a. The Herpesvirus "immediate early" transcription factor VP16 have cellular origin whereas adenovirus packs the "immediate early" E1A transcription factor in the virion b. Herpesvirus uses a cascade regulation unlike Adenoviral autoregulation c. Herpesvirus packs its RNA polymerase but Adenovirus do not d. The "immediate early" transcription factor VP16 is packaged into the Herpesvirus virion but Adenovirus use cellular transcription factors for its "immediate early" transcription
d. The "immediate early" transcription factor VP16 is packaged into the Herpesvirus virion but Adenovirus use cellular transcription factors for its "immediate early" transcription
Which of the following attributes to the specificity of RNA polymerases towards NTPs over dNTPs? a. The 2` hydroxyl of the deoxy-ribose sugar b. The 2` hydrogen of the ribose sugar c. The UTP d. The 2` hydroxyl of the ribose sugar
d. The 2` hydroxyl of the ribose sugar
Reverse transcriptase is an enzyme with low fidelity and low processivity. Which of the following statement best suites the above definition? a. The enzyme often incorporates wrong nucleotides as its synthesis rate is very fast b. The enzyme is always capable of incorporating correct nucleotides at a very high rate of synthesis for a productive viral infection c. The enzyme incorporates always correct nucleotides but in doing so the synthesis rate is also slow d. The enzyme often incorporates wrong nucleotides and its synthesis rate is slow as well
d. The enzyme often incorporates wrong nucleotides and its synthesis rate is slow as well
Which of the following is NOT true about the second strand (+) strand DNA synthesis of a typical retroviral (e.g. Avian Leukosis Virus: ALV) reverse transcription? a. The second strand synthesis stops temporarily at the modified base of the tRNA attached to the first strand before template exchange b. A polypurine tract (ppp) from RNaseH terminal digestion product serves as the primer for the second strand synthesis c. All of the other statements are true about the second strand (+ strand) DNA synthesis of a typical retroviral (e.g. Avian Leukosis Virus: ALV) reverse transcription d. The first template exchange synthesize the second DNA strand
d. The first template exchange synthesize the second DNA strand
Which of the following is NOT correct about the first strand DNA synthesis (the minus strand) in a typical retroviral (e.g. Avian Leukosis Virus: ALV) during reverse transcription? a. RNaseH degrades the RNA template from the RNA-DNA duplex concurrently with the DNA synthesis b. The initial segment of the DNA is synthesized as "strong stop" DNA c. tRNA bound to pbs acts as the primer for DNA synthesis d. The initiation site is close but not exactly at the 3` end of the retroviral genome e. All of the above/other are correct about the first strand DNA synthesis during reverse transcription
d. The initiation site is close but not exactly at the 3` end of the retroviral genome
Which signature structure of the tRNA is used as a reverse transcription primer, binding to pbs (primer binding site) in a typical (e.g. Avian Leukosis Virus: ALV) retroviral genome? a. The acceptor arm b. The anticodon loop arm and c. The D loop and arm d. The ΤψC loop and arm
d. The ΤψC loop and arm
Which of the following is the signature structure of a DNA binding domain of a transcriptional activator protein? a. Dimerization domain b. Leucine zipper c. Cloverleaf structure d. Zinc finger
d. Zinc finger
Which of the following protein is NOT involved in viral DNA replication? a. DNA dependent DNA polymerases b. Exonucleases c. Topoisomerases d. Helicases e. All of the mentioned proteins are involved in viral DNA replication
e. All of the mentioned proteins are involved in viral DNA replication
Which of the following statement about reverse transcriptase (RT) is NOT correct? a. Might have bridged the ancient RNA world and the DNA world b. The reverse transcriptase holoenzyme also has RNase H activity c. The name of the enzyme comes from its ability to reverse the flow of genetic information d. RT is packaged in the retrovirus particle e. RT is unique to retroviruses
e. RT is unique to retroviruses