What are two different ways cells of the body signal each other? Give an example of each.

Electrical signal, e.g. when you touch something hot, an electrical signal goes from your hand to your brain to tell you to pull your hand away. How do you know it's electrical? Because it's so fast!

Chemical signal, e.g. when you're frightened, a chemical signal goes from your brain into your blood to make you shaky and your heart beat faster. How do you know it's chemical? Because it takes a long time to grow, and a long time to go!