Virus Structure

Viruses are tiny infectious agents that consist of genetic material (DNA or RNA) surrounded by a protein coat called a capsid. Some viruses also have an outer envelope made of lipid (fat) molecules, which they acquire from host cells. The genetic material carries instructions for the virus to replicate itself inside host cells. Viruses cannot reproduce on their own; they must infect a living cell to multiply. Their simple structure allows them to invade host organisms and cause diseases, but they are not considered alive because they lack cellular machinery.