Regarding a recent question about viruses and virus-infected cells.
Viruses do NOT replicate by a mechanism anything like mitosis or
meiosis. Instead, the virus particle's function is largely to deliver its
genetic information, in the form of a DNA or RNA molecule, into the cyto-
plasm of a cell wherein the machinery of the cell synthesizes viral proteins
and copies of the viral genome (nucleic acid) so that new virus particles can
be assembled. What we are dealing with here is a directed synthesis of various
component parts of the virus particle and their assembly into new particles.
An infected cell is NOT a virus. IT is a cell which contains the
genetic information of the virus and, in most instances, is producing new
virus particles. The cell is needed because viruses cannot otherwise
make its proteins or synthesize nucleotides and other carbon compounds
needed for making its component parts. All this synthesis requires chemical
energy and cell is needed to provide it in the form of ATP and like compounds.
An infected cell may die as a consequence of virus infection or it
may not- the latter case being a persistent virus infection. In an animal,
it is the immune system that often destroys the persistently infected cells
so that these factories for virus production are eliminated.
I hope this answers the questions posed.