Bacteria

• dictionary: ubiquitous one-celled organisms, spherical, spiral, or rod-shaped and appearing singly or in chains, comprising the Schizomycota, a phylum of the kingdom Monera (in some classification systems the plant class Schizomycetes), various species of which are involved in fermentation, putrefaction, infectious diseases, or nitrogen fixation
• kid definition: germs that comes in different shapes and sizes that have different purposes
• sentence: At least one million bacteria are in our mouth!

a magnified image of a specific type of bacteria, bacilli