Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 117

1 Which of the following statements is not correct?The infectious cycle and virus reproduction are synonymousA susceptible cell has a functional receptor for a given virusA cell that is resistant to infection has the viral receptor but the virus cannot be reproduced in itVirus can be reproduced in a permissive cellA susceptible and permissive cell is the only cell in which a virus can enter and be reproduced

2 Which of the following statements about cytopathic effects (CPE) is correct?Some viruses may not produce cytopathic effects in certain cellsSyncytium formation is a type of CPERounding up and detachment of cultured cells is a type of CPEFormation of a viral plaque depends upon CPEAll of the above

3 Which of the following assays determines the number of infectious viral particles?ELISAHemagglutination assayPlaque assayHigh-throughput sequencingPolymerase chain reaction

4 If one million infectious virus particles are added to a culture dish of one million cells, which of the following will happen:Each cell will receive one virus particle because the MOI is 1None of the cells will receive any virus particles37% of the cells are uninfectedOnly one infectious cycle will take placeNone of the above

5 When doing a plaque assay, what is the purpose of adding a semisolid agar overlay on the monolayer of infected cells?To stabilize progeny virionsTo ensure that cells remain susceptible and permissiveTo act as a pH indicatorTo keep cells adherent to the plate during incubationTo restrict viral diffusion after lysis of infected cells

6 In the particle-to-PFU ratio, “particle” can best be described as:One of the proteins which makes up the virionA virus which may or may not be infectiousA virus which is infectiousA virus which is not infectiousElementary or composite

7 The plaque assay plate below was made from a dilution of 10–6 and 0.1 ml of the dilution was plated on the cell monolayer. What is the titer in PFU/ml?

8 Explain why no infectious viruses are observed in the cell culture medium during the latent phase of a onestep growth curve.

9 You infect a plate of one million cells at an MOI of 100. The particle-to-PFU ratio for this virus is 1,000. How many total virus particles did you add to the cells?