How is a virus different from bacteria?

Bacteria are able to replicate on their own and do not need a host cell. Viruses need to enter a host cell and use the host cell DNA to replicate and form new virions. The virions then bud out of the host cell or cause it to burst (lysis) before infecting new host cells so that the virus can replicate once more. Bacterial genes are found on a loop of DNA and they can also have a second smaller loop of DNA called a plasmid which viruses do not have. Viruses can contain either DNA or RNA in their nucleic acid core and have no cell organelles and are much smaller than bacteria.