What are bacteria?

Bacteria are small living microorganisms that vary in shape and size. Similar to plants cells they contain a cell wall, however, they do not have a nucleus. Instead their genetic information is carried in etiher plasmids or chromosomal DNA.Bacteria can rapidly reproduce without the aid of a host cell. This is unlike viruses that require a host cell to replicate within. Some bacteria also have flagella, these are tail-like structures that allow bacteria to become motile. They can cause damage to a host by releasing toxins this causes disease. Diseases that are caused by bacteria include, cholera, food poisoning and whooping cough.