a False a True a True Chapter 5 Homework except a 1 By virtue of their reproductive cycle all viruses must possess a mechanism for all of the below Incorporating their genetic material into the host genome 2 If the envelope of enveloped viruses is derived from the host cell during budding how does the new viral particle recognize and attach to a new host cell a Viral proteins needed for recognition and attachment on new host cells are embedded 3 In a plaque assay to determine virus titer a 1ml inoculums from a 10 7 dilution yields 225 plaques The original phage titer was in the envelope a 2 25 x 109 ml 4 The fact that no single gene is present in all viruses suggests a Viruses most likely arose from multiple lineages 5 The ability of scrapie to be transmitted from sheep to sheep is evidence that the disease a Is caused by an infectious agent 6 A solution that is sterile contains no bacteria but may contain viruses 7 Just like a bacterial colony is though to be the result of the repeated cell division of a single cell viral plaques are thought to be the progeny of a single virus particle 8 Mad cow disease can be transmitted to humans by eating infectious beef a RNA or DNA single or double stranded circular or linear single nucleic acid molecule or 9 Identify the different types of viral genomes composed of several individual fragments 10 A cytopathic effect is a A change in cells that occurs during viral replication Depending on the cell type and virus type these effects can range from cell death to morphological changes Some viruses cause the membranes of infected cells to fuse with other cells resulting in the production of a large multi nucleated cell called a syncytium 11 Which of the following is not a strategy used to name viruses a After the organelle they attack b Name them after the location where they were first noticed after the disease they cause after their morphology and after other physical characteristics 12 The Baltimore classification scheme categorizes viruses into a Seven different categories based on their genomic structure and their replication strategy 13 Nucleocapsids are composed of a A combination of nucleic acids and proteins 14 The fundamental premise of the coevolution hypothesis for the origin of viruses is a Viruses evolved at the same time as their host cells 15 The fundamental premise of the regressive hypothesis for the origin of viruses is a Viruses were once independent calls that became dependent on host cells 16 The plaque assay for determining viral titer measures a Only infectious viral particles 17 Viral quantification is complicated by the fact that a Not all viruses have observable effects on host cells 18 The most reliable way to identify a virus is by a Nucleic acid analysis 19 A prion is a An abnormally shaped protein 20 Viruses are obligate intracellular parasites 21 A prophage is an immature virus particle just prior to assembly 22 Viroids only infect plants 23 Kuru and mad cow disease are caused by viroids a True a False a True a false
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