A brief discussion of what makes a virus a retrovirus, and how they differ from other types of viruses.
Viruses are highly diverse in shape and size. HIV is a retrovirus. What kind of virus is a retrovirus? Some viruses use DNA for their genomes, and others use RNA. What does HIV use?
Also featured on the HHMI DVD, AIDS: Evolution of an Epidemic, available free from HHMI.