Rotten apples

Protect your child’s health by using this experiment to demonstrate how germs are passed.

You'll Need

  • One good apple
  • One bad apple (mushy and brown)
  • Toothpick
  • Paper towels
  • Marker

Learning Stages

Demontrate to your child the scientific truth behind the saying “One rotten apple spoils the whole barrel.” This experiment will show why so many people can get sick at the same time.

  1. Place the good apple on a piece of paper towel, and label it HEALTHY.
  2. Place the bad apple on a piece of paper towel, and label it SICK.
  3. Take a toothpick and stick one end into the sick apple, and the other end into the healthy apple.
  4. Wait about 10 minutes, then take the toothpick out. Throw out the sick apple.
  5. In 2-3 days, cut open your healthy apple.
  6. Ask your child to think about what happened to the healthy apple to make it sick.

Explain to your child that the toothpick transferred the bacteria (one-celled organisms that produce substances that build up or break down organic materials) from the sick apple to the healthy apple. This is what happens when someone who is sick passes on their germs to other people, by touching or breathing. This is why you should wash your hands before eating and cover your mouth when you cough.

Reading Resources

Germs Make Me Sick by Melvin Berger, illustrated by Marilyn Hafner (HarperTrophy, 1995)

The Magic School Bus Inside Ralphie: A Book About Germs by Joanna Cole, illustrated by John Speirs and Bruce Degan (Scholastic Paperbacks, 1995)

Wash Your Hands by Tony Ross (Princess Books, 2006)