Viruses use the host's machinery to make copies of themselves. However, some human viruses require a type of replication that humans do not normally do. For example, humans normally do not have the ability to convert RNA into DNA. How can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires?
A) Viruses can stay in a quiescent state until the host cell evolves this ability.
B) The virus infects only those cells and species that can perform all the replication roles necessary.
C) The virus causes mutations in the human cells, resulting in the formation of new enzymes that are capable of performing these roles.
D) The virus has in its own genome the code for any specialized enzymes that the host does not have.
E) All of the above have been frequently observed.

Question

Quizplus · Accepted Answer

Some viruses, such as retroviruses, carry their own specialized enzymes, such as reverse transcriptase, that can convert RNA into DNA. Therefore, the virus does not rely on the host's machinery to perform this role.

Viruses Use the Host's Machinery to Make Copies of Themselves