Final answer:
Retroviruses contain RNA instead of DNA and use reverse transcriptase to synthesize a DNA version of their genes. This DNA is integrated into the host cell's genome and used to produce viral proteins.
Step-by-step explanation:
Retroviruses have a basic genetic sequence that contains RNA instead of DNA. When a retrovirus infects a cell, it uses a specialized viral polymerase called reverse transcriptase to synthesize a DNA version of its RNA genes.
This DNA is then integrated into the host cell's genome. The viral DNA is transcribed into mRNA and translated into proteins, which are used to assemble new viruses.
The human immunodeficiency virus (HIV) is an example of a retrovirus.