Lucy and Ethel bake bread but put too much yeast. This clip can be used as an introduction to teaching about microorganisms such as yeast. It illustrates just how fast yeast grows and the role it plays in baking.
The Eds are making pizza, and they need to correctly measure the ingredients they put in the dough and the sauce. Eddy ignores Double D's measurement for yeast and has trouble kneading the dough. Although the yeast wouldn't grow until they baked the dough in the oven, this clip illustrates how fast yeast can grow.
Beakman explains that bread is an important food staple and there are different kinds of bread. He uses an animated clip to give some history of people creating bread. Then he explains the science behind how bread is made. Beakman uses a demo of yeast with water and sugar to show that yeast are living and create carbon dioxide and that's how bread rises.