Petri dish

A petri dish is a special type of dish that scientists use to study living things, like bacteria or fungi. It looks like a shallow dish with a lid, and it has an evenly-spaced grid of tiny holes in the bottom. Scientists put a special kind of jelly (called agar) in the dish, then put the living things they want to study on top. The living things need the jelly in order to grow and move around. The lid prevents things from getting in or out of the dish, so they can study the living things in an enclosed area.