front 1 In what ways do viruses differ from other pathogens? | back 1 Viruses lack cytoplasm & organelles |
front 2 The outermost layer of a virion fulfills which of the following functions of the virus? | back 2 both protection & recognition |
front 3 A n ______ is a virus that infects bacterial cells. | back 3 bacteriophage |
front 4 Which of the following is a characteristic by which viruses are classified? | back 4 type of nucleic acid |
front 5 Host specificity of a virus is due to | back 5 interactions between viral and cellular surface molecules |
front 6 Which of the following is primarily responsible for the shape of a virion? | back 6 the capsid |
front 7 How are fungal viruses different from viruses that infect other organisms? | back 7 they have no extracellular state. |
front 8 Which of the following infectious particles do NOT have protein in their structure? | back 8 viroids |
front 9 Which of the following may occur in a lysogenic infection, but not a latent one? | back 9 The inserted viral DNA may leave the host DNA |
front 10 Which of the following statements regarding virus taxonomy is true? | back 10 Some virus family names are derived from the name of an important member of the family. |
front 11 Which of the following statements comparing virus classification and taxonomy of organisms is true? | back 11 Genus and specific epithet are used in both classification systems. |
front 12 Which of the following places stages of a lytic replication cycle in order, from earliest to latest stages? | back 12 III, V, I, II, IV |
front 13 Which of the following is associated with the attachment of a bacteriophage to a bacterial cell? | back 13 random collisions, chemical attractions, and receptor specificity |
front 14 The enzyme lysozyme is critical for which of the stages of a bacteriophage T4 infection cycle? | back 14 entry and release |
front 15 Which means of entry into host cells is common to both some animal viruses and bacteriophage T4? | back 15 direct penetration |
front 16 Which of the following events occurs in the lytic cycle of bacteriophage T4 infection but NOT in the lysogenic cycle? | back 16 digestion of host DNA |
front 17 Why is lysogen advantageous to a bacteriophage? | back 17 The genetic material of the bacteriophage is amplified many times over that seen in a lytic phage. |
front 18 Which of the following agents is capable of inducing conversion of a prophage to the lytic cycle? | back 18 both UV light and X-rays |
front 19 Zones of clearing in cell cultures that are the result of virus infection are called plaques. Sometimes "cloudy plaques" are seen on bacteria cultures infected with bacteriophage. What type of viral infection might cause this appearance? | back 19 lysogenic |
front 20 Which of the following is matched Incorrectly? | back 20 adenovirus; membrane fusion |
front 21 Reverse transcriptase is associated with which of the following? | back 21 retroviruses |
front 22 The genome of which of the following types of animal virus can act directly as mRNA? | back 22 +ssRNA viruses |
front 23 Which of the following types of animal virus requires RNA-dependent RNA transcriptase to be replicated? | back 23 -ssRNA viruses |
front 24 In contrast to most dsDNA animal viruses, the poxviruses replicate solely in the cytoplasm of the host cell. this fact implies that the viral genome may encode | back 24 a DNA polymerase |
front 25 Which of the following membranes can give rise to a viral envelope? | back 25 the nuclear and cytoplasmic membranes and the endoplasmic reticulum |
front 26 A cell is infected with a virus carrying an oncogene sequence in its genome. What process may occur if the oncogenes expressed in the infected cell? | back 26 neoplasia |
front 27 How is the HIV provirus different from a lambda-phage prophage? | back 27 The HIV provirus is integrated permanently into the host cell's DNA |
front 28 Which of the following laboratory procedures is used for culturing animal viruses in the laboratory? | back 28 both cell cultures and embryonated eggs |
front 29 One mechanism by which viruses may cause cancer is to interrupt the genetic regulatory sequences of repressor proteins. which of the following types of viruses is most likely to be involved in causing cancer by this mechanism? | back 29 retroviruses |
front 30 Tumors invade other organs and tissues in a process called | back 30 metastasis |
front 31 Plaque assays are used for | back 31 determine the density of phage in a culture. |
front 32 Diploid cell cultures and continuous cell cultures differ in which of the following ways? | back 32 both longevity and source of cells |
front 33 Viroids infect | back 33 plants |
front 34 How are prions different from all other known infectious agents? | back 34 they lack nucleic acid |
front 35 The viruses of fungi have RNA genomes and lack a capsid. they are therefore similar to | back 35 prions |
front 36 A lipid membrane is present in which of the following? | back 36 enveloped viruses |
front 37 Some human viruses are difficult to study because | back 37 they only grow in normal human cells. |
front 38 Double stranded RNA genomes can be found | back 38 only in viruses |
front 39 Which of the following is a feature shared by viruses and living organisms? | back 39 possession of a genome that directs synthesis of materials necessary for replication |
front 40 Small circular RNA molecules without capsids are characteristic of | back 40 viroids |
front 41 Viruses are shed slowly and steadily during | back 41 lysogenic infection |
front 42 During _____ viruses remain dormant in animal cells. | back 42 latency |
front 43 Virus replication results in the death of the cell in ______ infections. | back 43 a lytic |
front 44 A ______ is a mass of neoplastic cells. | back 44 tumor |
front 45 The process known as ______ is a mechanism of release for enveloped viruses. | back 45 budding |
front 46 The combination of a virus's protein coat and nucleic acid core is called the (capsid/ virion/ nucleocapsid). | back 46 nucleocapsid |
front 47 Viral capsids are composed of subunits called (nucleocapsids/ capsomeres). | back 47 capsomeres |
front 48 Virus infection is initiated by the specific (fit/affinity/interaction) between proteins on the surface of a virion the surface of the target cell. | back 48 affinity |
front 49 Some viruses can be cultured on (continuous/diploid/animal) cells which are descended from neoplastic cells. | back 49 continuous |
front 50 The virions shown in the figure have a (polyhedral/ helical/ complex) capsid. | back 50 complex |
front 51 Another term for a lysogenic phage is a (temperate/ latent/ prophage) phage. | back 51 temperate |
front 52 The process in which viral capsids are removed within the infected cell is called (entry/ disassembly/ uncoating). | back 52 uncoating |
front 53 Uncontrolled cell division in animals is known as (metastasis/ neoplasia/ cancer). | back 53 neoplasia |
front 54 RNA viruses such as HIV require the activity of reverse (transcriptase/ polymerase) to become proviruses. | back 54 transcriptase |
front 55 In enveloped viruses, virus-encoded (matrix/ capsomers/ envelope) proteins are required for the assembly of the envelope around the capsid. | back 55 matrix |
front 56 Genes that play a role in proper cell division but may also play a role in some types of cancer are called (oncogenes/ protooncogenes/ promoters) | back 56 protooncogenes |
front 57 A (colony/ plaque) is a clear zone on a bacterial lawn where cells have been killed by the activity of a bacteriophage. | back 57 plaque |
front 58 Three (orders/ families/ classes) represent the highest level of taxonomic rank uses in classifying viruses. | back 58 orders |
front 59 Prions are composed of a single protein called (plaque/BSE/ PrP). | back 59 PrP |
front 60 An animal virus that does not have an envelope is described as a (naked/ unenveloped/ capsid) virion. | back 60 naked |