What type of organic molecule are viruses primarily composed of?

Viruses are primarily composed of nucleic acids, which can be either DNA or RNA. This nucleic acid is the genetic material that contains the information necessary for the virus to replicate and produce new viral particles. While viruses may have a protein coat, known as a capsid, that protects their genetic material, their central structure revolves around the nucleic acids. Some viruses also have an outer lipid envelope derived from the host's cell membrane, but this is not a defining feature of all viruses.

The key characteristic that distinguishes viruses is their reliance on nucleic acids to carry genetic information, which is essential for their infectivity and replication within host cells. Therefore, the focus on nucleic acids as the primary component aligns with their biological function and structure.