Explanation:

All living things have DNA, but technically speaking, viruses aren't living things because they can't maintain themselves or reproduce on their own. They also aren't technically cells because they don't have organelles -- cellular machinery -- of their own. They don't fit into any of the kingdoms of life -- they aren't plants, animals, fungi, protists, bacteria or archaea -- but there are viruses that infect every one of these. Viruses exist only as infectious agents. They're made up of a nucleic acid -- either DNA or RNA -- surrounded by a protein capsule. They only become active after entering a host cell.