NextPrevious

Biology

Viruses, Bacteria, Protists, and Fungi

What is a virus?

A virus is an infectious, protein-coated fragment of DNA or RNA. Viruses replicate by invading host cells and taking over the cell’s “machinery” for DNA replication. Viral particles can then break out of the cells, spreading disease.



Close

This is a web preview of the "The Handy Science Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App