UA Q&A: Is a virus a living thing? How can you tell?

Jeannine Durdik, professor of biological sciences in the J. William Fulbright College of Arts and Sciences, replies:

Viruses are not classified in the kingdom of living things, and the question of whether or not they are living organisms is still an open one in the scientific community. Some biologists see the virus as a nonliving infectious particle. Others believe it is alive because of its ability to manipulate the host cell.

A virus is little more than a strand of DNA or RNA with a protein coating. Viruses cannot reproduce on their own - they require a host cell, which they invade, injecting their genetic information into the hosts' DNA and forcing it to reproduce the viral DNA and other virus parts. Think of a virus as a renter without a security deposit.