The Human Immunodeficiency Virus (HIV) is a retrovirus.
It has the enzyme reverse transcriptase to copy the RNA genome into DNA, which is integrated into the host genome as a provirus, where it remains a permanent resident.
The host's RNA polymerase transcribes the proviral DNA into RNA molecules, which may function both as mRNA for synthesis of viral proteins and as new viral genomes.
AZT and reverse transcriptase
Review and exercise: