Microbiology chapter 13 Quizes and Complete answers

Microbiology chapter 13 Which statement is INCORRECT concerning animal viruses? a) Enveloped viruses are surrounded by a lipid and carbohydrate coat, which is made from the host cell's plasma membrane. b) Capsid proteins are produced in the cytoplasm. c) Retroviruses use an enzyme called reverse transcriptase, which synthesizes DNA using RNA as a template. d) The genome of animal viruses is always single-stranded. ANSWER: d A feature that may be found in viruses but never in bacteria is a) an ability to infect more than one type of host. b) the ability to pass through 0.22 micrometer pore filters. c) they cannot reproduce themselves outside a host. d) a sensitivity to antibiotics. e) may contain an RNA genome. ANSWER: e Why do most scientists agree that viruses are nonliving entities? a) They are not composed of cells. b) They cannot replicate outside host cells. c) They pass through filters. d) They cause diseases in host cells. e) They are composed of relatively simple components. ANSWER: a Which of the following statements about viral spikes is FALSE? a) They may cause hemagglutination. b) They bind to receptors on the host cell surface. c) They are composed of carbohydrate-protein complexes. d) They are found only on nonenveloped viruses. e) They are used for attachment. ANSWER: d The morphological types of viruses illustrated in the figure are ultimately determined by the nucleic acid. envelope. capsomeres. membrane spikes. viroids. ANSWER: a A viral species is a group of viruses that a) infects the same cells and cause the same disease. b) has the same genetic information and ecological niche. c) has the same morphology and nucleic acid.