The hypothesis is that yeast will make carbon dioxide when it decomposes food.

You will cut two slices from a banana, place each slice in a separate plastic bag, add yeast to one of the bags, and observe the bags for 3-4 days.

You will need two slices from a banana, two plastic sandwich bags, 1/2 tsp. of dry yeast, a plastic spoon and knife, tape and marker to label bags, pen and paper to record observations.

Through this experiment, you'll observe the effects of yeast on food decomposition. You may even notice that the bag with the yeast "blew up" more than the bag without the yeast.

This science project is interesting and unique because it allows students to explore the characteristics of the fungi group that causes yeast to feed on other organisms.

Experiment variations could include testing what effect yeast has on an apple or a piece of bread, or performing the experiment with a substance other than yeast.