Group Members: Ayla Duggan, Juan Miranda

Problem: How do you identify the pathogen that causes a specific disease?

Purpose: Which pathogen caused a disease?

Hypothesis: Our group thinks fungi is the pathogen because, it spreads and grows easily within a few days.

Materials: A slice of moldy bread (labeled as slice A), 2 slices of fresh bread (labeled as slice B and slice C), sterile Petri dish with agar, sterile cotton swabs, gloves, mask, and goggles. washable markers.

Procedure:

1. Have all your materials ready.(see list)
2. Put on your gloves, goggles, and mask.
3. Supply three bread pieces that are the same size.
4. Using a sterile cotton swab rub the moldy bread and then rub it onto the agar in the Petri dish.
5. Repeat with the other 2 slices of fresh bread.
6. On the cover of the Petri dish, use a washable marker to label accordingly.
7. Store in dry dark area.
8. Check for growth in 24 hours then again after three days and every day after until obvious results are found.
9. Record all findings.

Observation: We (Ayla and Juan) began working on this experiment on Thursday, October 14, 2004 at 1:30 p.m. Wearing gloves we each used a cotton swab and dabbed it onto a piece of moldy bread and then touch it onto the Agar. We repeated this process with a fresh piece of bread. Then we labeled the covers of the Petri dish accordingly with the letters M and F. We stored the Petri dishes in the bathroom of our science class room.

On Friday, October 15, 2004 Ayla checked for growth and there was no progress.

On Monday, October 18, 2004 we (Ayla,Juan) checked for growth and discovered there was a faint film of mold beginning to accumulate on the surface of the agar forming a speckled pattern in the Petri dishes labeled F.  In the Petri dish labeled M, it was clear that mold began to grow on the surface of the agar in a speckled pattern also; however it was much more obvious with the naked eye, where as we had to use a magnifying glass to see growth with the fresh specimen.

Conclusion: We predicted correctly. Fungi is the pathogen because the mold did spread and began to grow within a few days, and it was able to be observed without a magnifying glass.

Analyze and Conclude: Explain how your results either support or do not support your hypothesis. See my conclusion. Did slices A and B exhibit the same disease symptoms? Yes. According to your results, were you able to identify the pathogen that caused slice A to become moldy?  No, it probably formed because of the moistness and dampness of where it was stored caused a mold to grow. But we don’t know exactly what caused it. What was the purpose of slice C? Did it become diseased? Why or why not? Slice C was used as a back up to show more results if needed. Yes it did become diseased because it was exposed to the mold and we were able to observe the growth that resulted. What scientific methods were used in this Investigation? Question, Hypothesis, Observation, Experiment, Data, and Conclusion.