A scientist is deciding whether a virus in a growing tissue has followed the lytic pathway or the lysogenic pathway. An early sample contains living host cells with viral DNA incorporated into their host DNA. After several cell divisions, a later sample contains viral DNA in every living descendant cell. No complete virus particles are detected in either sample.
Which statement accounts for these results?
The lytic pathway assembled complete virus particles while keeping every host cell alive.
The lysogenic pathway copied the viral DNA with the host DNA during cell division.
The lytic pathway allowed the viral DNA to reproduce outside the living host cells.
The lysogenic pathway removed the viral DNA from the host DNA before each division.
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.