Bread Mold Growth Materials per group: Four self-sealing sandwich bags Four slices of bread (try to get 4 different kinds) Medicine dropper Beaker of water Sharpie

Procedure: 1. Obtain four slices of different types of bread. Touch each piece of bread to your desk or another surface in the room. 2. Use a medicine dropper to moisten each slice of bread with some drops of water on the side that you rubbed on a surface. 3. Place the bread in a sandwich bag. Label the sandwich bag with the type of bread, your group’s name and the class period. 4. Place the bread in a warm, dark location. 5. Write a hypothesis predicting the order in which the bread will mold.

Problem: Which type of bread shows the greatest resistance to mold?

Hypothesis: The bread slices will mold in the following order

First ______, Second ______

Third ______, Fourth ______

Record the number of “spots” and other observations in the chart below Observation Date Bread #1 Bread #2 Bread #3 Bread #4

Analysis and Conclusions:

While you are analyzing your bread mold samples be careful not to open your bag and expose the mold to the surface of your table, the air or the people around you.

1. When you are making observations of your fungal colonies, note the number of colonies, the diameter of them, color and other identifying characteristics. 2. Examine your bread with a hand lens, WITHOUT OPENING THE BAG. 3. Identify the following types of hyphae: sporangiophores, sporangia, stolons and rhizoids. (see page 368 and your handout for descriptions of these parts) 4. Make drawings of what you observe on all four types of bread. 5. Try to identify the types of molds. Page 368 tells you of some common types.

*when you are finished, dispose of the materials properly in the bin at the front

1. Which bread was the first to show mold growth?

2. Which bread showed mold growth second? Third? Last?

3. How did the appearance of the mold change over time?

4. Why did you rub the bread slices on a surface?

5. Why did you add water to the bread?

6. Why were all of the slices of bread put in the same place?

7. Why don’t dehydrated foods produce mold?

8. Why did mold grow faster on some bread slices than on other bread slices? Discussion The following needs to be included in your discussion  Did your data support or refute your hypothesis/  Restate your hypothesis  Describe your data in words  Check with other groups – did mold growth differ based on the surface on which the bread was rubbed  Do some research and explain your results…specifically, why did the breads mold at a different rate; what kind of mold was on your bread; what ingredients besides calcium propionate will keep your bread from molding; how can you store bread to keep it from molding  What did you learn from this lab?