: A virus consists of nucleic acid and protein. The nucleic acid, which can be either DNA or RNA, contains the virus’s genetic information. Surrounding the nucleic acid is a protein coat called a capsid, which protects the genetic material and aids in the virus’s attachment to host cells. In some viruses, there may also be a lipid envelope derived from the host cell’s membrane that surrounds the capsid, providing an additional layer of protection. Carbohydrates are not a primary component of viruses, but they may be present as part of the lipid envelope in some cases. Therefore, the primary components of a virus are nucleic acid and protein.