Viruses rely on the host cell machinery to make new viruses, but they sometimes provide their own enzymes (such as reverse transcriptase, which is an RNA-dependent DNA polymerase). Which of the following types of enzymes would a virus need to provide in order to replicate within a cell? In other words, which of these enzymes would not normally be found in a cell unless a virus provided it?

The correct answer is: RNA dependent RNA polymerase, also called, RNA replicase.

Explanation:

RNA dependent RNA polymerase or RNA replicase is an enzyme that is capable of replicating RNA. This means the enzyme is capable of utilising RNA (Ribonucleic Acid) as a template strand to synthesise a new RNA molecule as the daughter strand.This enzyme is encoded only in the genome of those viruses that use RNA as their genetic material and such viruses are called RNA viruses.This enzyme is absent in the host cells that the virus infect.These viruses hijack the host cell machinery to translate their RNA genome and synthesise the RNA replicase protein, which further helps in replicating their RNA genome.