Agar: A gelatin-like substance. If you mix it with other ingredients and pour the mixture into a petri dish to cool, you can grow bacteria on it!
Antibiotic: Medicine that gets rid of bacteria (your doctor might give you an antibiotic if you are sick with a bacterial infection).
Bacteria: Tiny microscopic living things that can be harmful or helpful, depending on the type.
Disinfectant: A substance, like bleach or soap, that gets rid of bacteria and viruses.
Infection: When harmful bacteria or viruses get inside your body and make you sick.
Petri dish: A container that scientists use to grow bacteria in.