MMSC 360 Exam 3 (100% Correct Solutions)

General Characteristics of Viruses- Introduction correct answers -'Filterable' - filter infectious material, filter causing infection smaller than bacteria -Viruses are only active inside host cell - cannot replicate outside of a host cell --Obligate intracellular parasite (OIP) General Characteristics of Viruses- Living vs. Nonliving correct answers -Viruses are acellular - do not have a true cell structure, no organelles -Unable to self-replicate --Viruses produced genome --Viruses do evolve - undergo mutations -Many scientists classify viruses as being nonliving because of the above characteristics General Structure of Viruses - Capsid correct answers -Capsid (protein coat) - capsids are made up of protomers --Helical- hollow cylinder --Polyhedral- icosahedral, 20 triangular sides ---Capsomeres --Complex - bacteriophage ---Has binding fibers that allow puncture into cell wall General Structure of Viruses - Nucleocapsid correct answers -Nucleocapsid --Capsid --Genetic material --Enzymes General Structure of Viruses - Envelope correct answers -Components- from host membrane, lipids, glycoproteins -Properties- environmentally labile (not very stable) -Naked capsid Classification of Viruses correct answers -Host range - viruses are very particular about their host -Pathogenesis --Arboviruses- viruses that are transmitted by arthropods (insects, mosquitos, ticks) --Tissue tropism - once they get inside the animal, where do they like to replicate? Classification of Viruses 2 correct answers -Genome - (RNA vs. DNA), typically only have one type of nucleic acid, single stranded vs. double stranded -Capsid --Number of capsomeres Classification of Viruses 3 correct answers -Enveloped vs. naked (envelope is outside of the capsid) -Size of virion - viruses are very small (smaller than bacteria)