Scientists compare a standard lytic virus with variant M. Each virus is added to a separate culture containing the same type and number of host cells. In each culture, 100 host cells are infected initially and the same large number of uninfected host cells remains available.
| Virus | Copies of viral genetic material made by 25 minutes | Viral protein molecules made by 25 minutes | Assembled virus particles present at 25 minutes | Host cells lysed by 40 minutes |
|---|---|---|---|---|
| standard virus | 12 400 | 620 000 | 10 800 | 82 |
| variant M | 12 100 | 610 000 | 160 | 3 |
Using the results, explain which stage of the lytic pathway is most likely to be interrupted in variant M.
Suggest how variant M will affect the number of newly infected host cells after 60 minutes, compared with the standard virus.
112 exam-style questions on Edexcel GCSE Biology 5.1 Health and communicable disease, covering 5.1.1 Communicable and non-communicable diseases, 5.1.2 Disease susceptibility interactions, 5.1.3 Pathogens as disease-causing organisms, 5.1.4 Common infections, 5.1.5 Spread and prevention of pathogens, 5.1.6 Lifecycle of a virus, and 5.1.7 Spread and prevention of STIs. Each one has a worked solution and a mark scheme showing where the marks go.