微生物题库下.pdf
微生物题库下Chapter 9:Essentials of Virology1)Viral replication isA)independent of the cells chromosomes but dependent on the cell itself.B)independent of both the cells chromosomes and the cell itself(although the cell does providea convenient matrix for replication).C)dependent on the cells chromosomes but independent of the cell itself.D)dependent on both the cells chromosomes and the cell itself.Answer:A2)Viral replication occurs in theA)intracellular state only.B)extracellular state only.C)both the intracellular state and the extracellular state.D)either the intracellular state or the extracellular state,depending on the virus involved.Answer:A3)Viral size is generally measured inA)micrometers.B)picometers.C)nanometers.D)attometers.Answer:C4)Enveloped viral membranes are generally with associated virus-specificA)lipid-bilayers/phospholipidsB)protein-bilayers/lipidsC)lipid-bilayers/proteinsD)glycolipid-bilayers/phospholipidsAnswer:C5)Which statement is true?A)All viruses contain their own nucleic acid polymerases.B)Some viruses contain the汗 own nucleic acid polymerases.C)Viruses do not contain their own nucleic acid polymerases.D)The origins of the nucleic acid polymerases used by viruses are eukaryotic in nature.Answer:B6)Reverse transcriptase is a(n)A)RNA-dependent DNA polymerase.B)DNA-dependent DNA polymerase.C)RNA-dependent RNA polymerase.第1页 第1页微生物题库下D)DNA-dependent RNA polymerase.Answer:A7)Viruses infecting are typically the easiest to grow in the laboratory.A)plantsB)animalsC)fungiD)prokaryotesAnswer:D8)End point dilution is the viral dilution point where the amount of virus present would belethal toA)all the animals injected.B)half the animals injected.C)none of the animals injected.D)only those animals already infected with the virus.Answer:B9)Cellular receptors may be composed ofA)proteins.B)carbohydrates.C)lipids.D)combinations of any or all of the above.Answer:D10)Restriction isA)the viral process whereby a hosts DNA ceases normal functioning.B)the viral process whereby the virus prevents other viruses from entering the cell.C)the cellular process whereby the host cell prevents the invasion of foreign nucleic acid.D)the cellular process viral particles are prevented from further infective action.Answer:C11)David Baltimore is credited with the discovery ofA)reoviruses.B)series viruses(such as T2,T4,etc.).C)parvoviruses.D)retroviruses and reverse transcriptase.Answer:D12)The simplest form of viral reproduction in RNA viruses is that which occurs with theA)positive-strand RNA viruses.B)negative-strand RNA viruses.C)positive-strand DNA viruses.D)negative-strand DNA viruses.第2页 第2页微生物题库下Answer:A13)The most common type of bacteriophage is thought to have a genome.A)single-stranded RNAB)single-stranded DNAC)double-stranded RNAD)double-stranded DNAAnswer:D14)A virus that kills its host is said to beA)virulent.B)temperate.C)lysogenic.D)virulent or lysogenic,but not temperate.Answer:A15)Which statement is true about the bacteriophages?A)T2 has been studied the most extensively.B)T4 has been studied the most extensively.C)T6 has been studied the most extensively.D)T2,T4,and T6 have all been studied to about the same degree.Answer:B16)The packaging mechanism of T4 DNA involves cutting of DNA fromA)linear genetic elements.B)circular genetic elementsC)DNA concatamers.D)none of these-they are all transcribed directly from inserted viral DNA.Answer:C17)A prophage replicatesA)along with its host as long as the lytic genes are being expressed.B)along with its host as long as the lytic genes are not being expressed.C)independent of its host as long as the lytic genes are being expressed.D)independent of its host as long as the lytic genes are not being expressed.Answer:B18)The virus repressor proteinA)controls the prophages lytic genes but not the incoming genomes of the same virus.B)does not control the prophages lytic genes but does control the incoming genomes of thesame virus.第3页 第3页微生物题库下C)controls both the prophages lytic genes and the incoming genomes of the same virus.D)has different actions in different situations.Answer:C19)Lambda is aA)temperate phage that infects E.coli.B)linear double-stranded DNA phage.C)one of the best studied lysogenic phages.D)all of the above.Answer:D20)Agents that induce lambda lysogens include which of the following?A)UV irradiationB)X-raysC)Nitrogen mustardsD)All of the aboveAnswer:D21)RetrovirusesA)transcribe DNA from RNAB)may cause cancer.C)include the virus that causes AIDS.D)all of the above.Answer:D22)The primer for retrovirus reverse transcription isA)cellular transfer RNA.B)cellular transfer DNA.C)nuclear transfer RNA.D)nuclear transfer DNA.Answer:A23)An integrated stable genetic element in a eukaryotic cellA)can occur anywhere in the cellular DNA.B)is called a provirus.C)is analogous to the integration of phage DNA into a bacterial genome.D)all of the above.Answer:D24)A viroidA)is a small,circular,single-stranded RNA molecule.第4页 第4页微生物题库下B)does not include a capsid of any kind.C)contains no protein-encoding genes.D)all of the above.Answer:D25)When packaged in the virion,the complete complex of nucleic acid and protein is known asthe virusA)capsid.B)capsomer.C)nucleocapsid.D)envelope.Answer:C26)Which of the following are the hosts for most enveloped viruses?A)BacteriaB)AnimalsC)ArchaeaD)FungiAnswer:B27)Plant viruses can be difficult to work with becauseA)their study sometimes requires the use of the whole plant.B)plants grow much slower than bacteria.C)plant viruses often require a break in the plant cell wall in order to initiate infection.D)all of the above.Answer:D28)Viruses possessing what type of nucleic acid are susceptible to destruction by prokaryoticDNA restriction endonucleases?A)Double-stranded DNAB)Single-stranded DNAC)Double-stranded RNAD)Single-stranded RNAAnswer:A29)What is the host protein that causes induction of bacteriophage lambda?A)Lambda repressorB)RecAC)CroD)Q proteinAnswer:B第5页 第5页微生物题库下30)Viruses can confer on their host cells properties that can in turn be inherited.Answer:TRUE31)Viruses have both an intracellular and an extracellular form.Answer:TRUE32)Viruses can redirect host metabolic functions.Answer:TRUE33)At the moment there is no formal system of viral taxonomy,although several systems arepresently being developed.Answer:FALSE34)There is at least one known virus whose genome is actually larger than a cellular genome.Answer:TRUE35)Some viruses possess icosahedral heads and helical tails.Answer:TRUE36)In the first few minutes after host cell infection the virus undergoes an eclipse.Answer:TRUE37)Penetration is possible because of changes resulting from the attachment of the virus to thecell.Answer:TRUE38)Some viruses encode host restriction systems designed to destroy host DNA.Answer:TRUE39)A viral infection always shuts down the hosts macromolecular synthesis system.Answer:FALSE40)Tailed bacterial viruses can be used as genetic engineering tools.Answer:TRUE41)Although T4 encodes over 250 proteins,it does not encode its own RNA polymerase.Answer:TRUE42)Temperate viruses can enter a state called lysogeny.Answer:TRUE43)Lysogeny is limited to bacteriophages;similar relationships have not been found amongstthe animal viruses.第6页 第6页微生物题库下Answer:FALSE44)A temperate virus does not exist in an extracellular form inside the host cell.Answer:TRUE45)The virus repressor protein is said to give immunity to infection by the same type of virus.Answer:TRUE46)A lytic infection results in the destruction of the host cell.Answer:TRUE47)In an animal cell,the latent stage of a viral infection is generally not due to integration ofthe viral genome into the host cell genome.Answer:TRUE48)When a virus enters a host cell in which it can replicate,the process is cal l ed.Answer:infection49)The term phage is generally reserved for the viruses that i nf ect.Answer:bacteria50)Rod-shaped viruses have symmetry and spherical viruses havesymmetry.Answer:helical/icosahedral51)An icosahedron has faces.Answer:2052)Regarding the viral membrane in an enveloped virus,the lipids are derived from theand the proteins are encoded by the.Answer:host/virus53)Virions infecting some bacteria possess the enzyme that makes a small hole inthe bacterial cell wall allowing the viral nucleic acid to enter.Answer:lysozyme54)The use o f has greatly enhanced research on most animal and many plantviruses.Answer:tissue or cell cultures(other answers might be possible)55)The smallest unit that causes a detectable effect when placed in a susceptible host is knownas a(n).Answer:virus infectious unit第7页 第7页微生物题库下56)A clear area in a lawn of growing host cells is known as a(n).Answer:plaque57)Two patterns of chemical modifications of viral DNA that work to overcome host restrictionmechanisms are and.Answer:glucosylation/methylation(either order)(other answers may be possible.)58)The process of copying information found in RNA into DNA is cal l ed.Answer:reverse transcription59)In terms of its viral genome,an ambivirus has.Answer:a single-stranded RNA genome half of which is plus and half of which is minus60)Viral proteins are categorized as early and late.Early proteins are,while lateproteins i ncl ude.Answer:necessary for replication of viral nucleic acid/those found in the protein coat61)A cell that allows multiplication of a virus to take place is said to be.Answer:permissive62)An infected cell undergoes cell lysis because the infectious phage codes for a.Answer:lytic enzyme(or lysozyme)63)Lambda and other temperate viruses have a genetic switch that.Answer:controls whether the lytic or the lysogenic pathway is followed64)The two events necessary to establish lysogeny for lambda phage are andAnswer:production of all late proteins must be prevented/temperate virus genome must beintegrated into the host genome(either order)65)The protein in the lambda phage that prevents the synthesis of the late proteins is theAnswer:lambda repressor66)The only lambda protein that is produced after the genome is integrated is.Answer:lambda represssor67)The enzyme involved in the transfer of RNA to DNA is.Answer:reverse transcriptase第8页 第8页微生物题库下68)The three enzymatic proteins found in the retrovirus particle are,and.Answer:reverse transcriptase/DNA endonuclease(integrase)/protease(any order)69)Gag,pol,and env are.Answer:retroviral genes found in all retroviruses and arranged in the same order70)In viruses genetic information flows from to.Answer:nucleic acid/protein71)The number of infectious units per volume of fluid is known as the.Answer:titer72)Transmissible spongiform encephalopathies(TSEs)are caused by.Answer:prions73)Explain the relationship between the terms virus particle,virion,and virus genome.Answer:Answers will vary.74)Explain the difference between an enveloped virus and a naked virus.Answer:Answers will vary.75)Explain the similarities and/or differences between permanent cell lines,primary cellcultures,and organ cultures.Answer:Answers will vary.76)How does efficiency of plating effect plaque-forming units?Answer:Answers will vary.77)Explain viral replication in terms of maturation,latent period,release,lysis,and burst size.Answer:Answers will vary.78)Describe the structure of the T4 virus and explain this virus attachment and penetrationprocesses in terms of this structure.Answer:Answers will vary.79)Describe the process whereby single-stranded DNA viruses are replicated.Answer:Answers will vary.80)Using T4 virions as a model,explain the concept of circular permutation.Answer:Answers will vary.第9页 第9页微生物题库下81)Describe the lytic pathway of lambda infection using the following terms:PL,PR,N gene,cro gene,antiterminator,ell,clllz Qgene,rolling circle replication.Answer:Answers will vary.82)Describe the establishment and maintenance of the lysogenic state in the lambda phage.Answer:Answers will vary.83)Explain lambda integration using the following terms:cos,cl,int,integrase,attachmentsites,excisionase,xis gene.Answer:Answers will vary.84)Why can it be said that induction of bacteriophage lambda is an indirect consequence ofthe SOS response?Answer:Answers will vary.85)Explain the concept of a persistent infection in terms of a virus infected cell.Answer:Answers will vary.86)Describe the seven steps of retroviral replication.Answer:Answers will vary.87)Since the prion is composed entirely protein,explain how the prion replicates.Answer:Answers will vary.88)Explain why some viruses contain enzymes within the virion and others do not.Answer:Answers will vary.89)Explain how to determine the number of plaque forming units in a virus sample.Answer:Answers will vary but should include a description of how the plaque procedure isperformed along with the definition of a plaque.90)Why is uncoating a step in the replication cycle of some animal viruses?Answer:Answers will vary.第 1 0 页 第 1 0 页微生物题库下Chapter 11:Microbial Evolution and Systematics1)The earliest stromatolites were probablyA)anoxygenic phototrophs.B)anoxygenic lithotrophs.C)oxygenic phototrophs.D)oxygenic lithotrophs.Answer:A2)The most abundant gases in the early atmosphere of the Earth were probablyA)CH4Z C02,02,N2.B)CH4,H2,02,N2.C)CH4,C02,N2,NH3.D)H2,C02,02,N2.Answer:C3)Probably the most important energy source available on primitive Earth wasA)thermal radiation.B)ultraviolet(UV)radiation.C)infrared(IR)radiation.D)radioactivity.Answer:B4)Compared to today,the temperature on Earth during its first half billion years was probablyA)considerably warmer(averaging perhaps 100).B)considerably colder(averaging perhaps 10).C)about the same as today.D)about the same as today on average but the diurnal fluctuations were much greater.Answer:A5)The earliest polymerization reactions probably took pl ace;these reactions wereaided by exposed surfaces.A)spontaneously/irregular,aqueousB)with enzymes/irregular,aqueousC)spontaneously/stable,anhydrousD)with enzymes/stable,anhydrousAnswer:C6)The earliest RNA probably functioned inA)catalysis.第1 1页 第1 1页微生物题库下B)genetic coding.C)both catalysis and genetic coding.D)neither catalysis nor genetic coding.Answer:C7)Chemical reactions involving have been proposed as energy yielding reactionsfor primitive organisms.A)iron,oxygen,and hydrogenB)sulfur,oxygen,and hydrogenC)iron,sulfur,and oxygenD)iron,sulfur;and hydrogenAnswer:D8)Even today the most primitive energy conserving reactions are still carried out by theA)Bacteria.B)Archaea.C)Eukarya.D)Bacteria and Archaea.Answer:B9)The cyanobacteria probably evolved fromA)anoxygenic phototrophs.B)anoxygenic lithotrophs.C)oxygenic phototrophs.D)oxygenic lithotrophs.Answer:A10)Identification of the three domains,Bacteria,Archaea,and Eukarya,has come aboutprimarily as a result ofA)advanced methods of morphological examination.B)biochemical assays.C)analyses of metabolic pathways.D)nucleic acid sequencing studies.Answer:D11)Metazoans have existed for approximately how much of Earths history?A)One halfB)One thirdC)One sixthD)One tenthAnswer:C12)The most widely used molecular chronometer isA)DNA.第1
