Anew mother is trying to stop her baby boy from crying. she tries out many different options. she finds that giving him his favorite toy for 10-min of playtime, followed by feeding him a half-cup of warm milk immediately stops his crying. now every time she wants her son to stop crying, she employs this effective

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 have. 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) the virus causes mutations in the human cells, resulting in the formation of new enzymes that are capable of performing these roles. b) the viral genome codes for specialized enzymes not in the host. c) the virus infects only those cells and species that can perform all the replication roles necessary. d) viruses can stay in a quiescent state until the host cell evolves this ability.