Question

Provirus differs from prophage in
A. Integration of copy DNA of a retrovirus with eukaryotic chromosome (DNA)
B. Integration of RNA with host DNA
C. Integration of genetic DNA with host DNA
D. All of the above

Answer 1

Hint: A provirus is the genome of a virus that is inserted into a host cell's DNA. If a (non-endogenous) retrovirus invades a cell, integration may result in a latent infection or a productive infection if the RNA of the retrovirus is invaded.

Complete answer:
The provirus is a retrovirus with a special enzyme called reverse transcriptase that can transform the single-stranded RNA genome into double-stranded viral DNA that is integrated as a provirus into the host genome and can be passed on to progeny cells. The provirus is introduced into the genome of eukaryotes.
Prophage is produced in the lysogenic cycle in which the viral genome is inserted into the bacterial chromosome instead of taking over the power of the host's biosynthetic machinery.
Prophage is the genome of T phage (mostly T2&T4), while provirus is the genome of the retrovirus and is integrated into the prokaryotic genome.
Accordingly, We may deduce that prophagia is simply DNA, while provirus is a copy of DNA formed from the transcription of the reverse RNA strand.
Hence, option A: Integration of copy DNA of a retrovirus with eukaryotic chromosome (DNA) is the correct answer.

Additional Information: The formation of Provirus is a particular strategy among animal viruses and positions retroviruses among the retrotransposons-known mobile factor classes. The virus mimics a cellular gene in the DNA intermediate stage and relies almost entirely on the host-cell gene expression machinery.

Note: A special enzymatic mechanism shared by all retroviruses and retrotransposons is DNA integration. During incorporation, in a process catalysed by the virus-encoded integrase (IN), double-stranded linear viral DNA is incorporated into the host genome.