The Magic School Bus In a Pickle
Microbes turned Arnold's tomato into a goopy, ploopy mess. Here, your students can discover what microbes need to grow -- and how cold affects microbe growth - by growing bread mold.
- Grades: 3–5
Field Trip Notes
Order in the court! When Keesha comes back from vacation, her prizewinning cucumber is missing - replaced by a pickle. Could Ms. Frizzle, who has a passion for pickles, be the culprit? The Friz says a group of tiny troublemakers called the Mike Robe Gang (microbes) is responsible. But they're too tiny to see. The bus shrinks to housefly size, and the kids find evidence that millions of the gang members are changing things all around them. At the scene of the crime, they discover that microbes pickled the cucumber, saving it from spoiling. Case closed!
Time: 10 minutes every day for eight days
Group Size: Three or four
Microbes turned Arnold's tomato into a goopy, ploopy mess. Here, your students can discover what microbes need to grow - and how cold affects microbe growth - by growing bread mold.
What You Need
- Masking tape
- Marking pens
- Copies of GETTING MOLDY
For each group:
- Two slices of bread (try bakery bread - no preservatives)
- Two zip-lock baggies
Talk About It
Ask kids: Where have you seen mold? How do you think it got there? (Molds are large groups of microbes; microbes are in the air we breathe, on everything we touch and see.) What do you think cold does to mold?
What To Do
- Have each group put a slice of bread into a baggie, seal the bag, and label it WARM. Place that slice on a shelf or desk where kids can observe it easily.
- Groups place second slice of bread into a baggie, seal bag, and label it COLD. Place baggie in refrigerator.
- Have students observe both baggies daily, and draw what they see. (Bread contains water; they may see moisture in the bag.)
- After mold is visible ask: What’s on the bread? How is the mod changing the bread? Is there more mold on one slice? (WARM) Why? (Cold retards mold growth.)
- Dispose of bread and bags properly.
If you are near a pond, collect some water in a quart jar. Examine some of the water with a microscope or a magnifying glass. (You should see plenty of microbes!) Ask: How can you find out more about what you see?