No prizes for guessing the first thing you'll need: a microscope. But don't worry if you don't have one of your own. Ask your school if they have one you can use. Then you'll need an onion.

No prizes for guessing the first thing you'll need: a microscope. But don't worry if you don't have one of your own. Ask your school if they have one you can use. Then you'll need an onion.