Principles of Medical Virology Quiz

See Virion Without a Factory. Option D is correct. Susceptibility concerns whether a virus can gain entry to a cell, usually through suitable receptors. Permissiveness concerns what happens once it is inside: the cell must provide conditions that allow viral replication and production of new infectious particles. A cell can therefore admit a virus yet fail to support its full replication programme. Conversely, a cell may have suitable internal machinery but lack the receptor needed for normal entry. A useful analogy is a door and a workshop: access through the door does not guarantee that the workshop can complete the job.

E confuses susceptibility with lysis, the breaking open of a cell, and permissiveness with antibody binding; these are separate events. Detectable virus in blood (A) is viraemia and says nothing by itself about these properties of an individual cell. B makes progeny output the definition of entry access and integration the definition of replication support, although many viruses replicate without inserting DNA into a host chromosome. C names both relevant processes but attaches them to the wrong terms.