This document outlines a project-based learning activity where students will investigate which foods mold grows the most and least on, and which environments promote the most mold growth. Students will take samples of different foods, subject some to different conditions like cooking or wetting, and observe their mold growth over time in various environments like the refrigerator or in sunlight. They will analyze why wet, uncooked foods left in the sun should mold the fastest, while cooked, refrigerated foods should mold the slowest, based on molds' needs for water, nutrients, and warm temperatures to thrive. The goal is for students to gain experience with scientific experimentation while learning about the factors that influence mold growth.

1. Activity 2: Project-Based Learning: How Does Mold Grow?
Project-based learning (PBL)
PBL is a holistic instructional strategy that brings students as close to real world applications as
possible in an educational context (M3U4A2, 2015). Project Based Learning is a teaching
methods in which students gain knowledge and skills by working for an extended period of time
to investigate and respond to a complex question, problem, or challenge (Bjornson, 2013).
Key Knowledge, Understanding, and Success Skills
The project is focused on student learning goals, including standards-based content and skills
such as critical thinking/problem solving, collaboration, and self-management (M3U4A2, 2015).
Mold is a fungus that needs nutrients and water to grow. Mold can be found indoors and
outdoors all over the world. Most are non-toxic, but they certainly aren't good to eat! Mold can
grow on surfaces like rocks and walls, but in homes it commonly grows on aging food. Many
foods, especially bread, contain mold inhibitors and preservatives to prevent mold from
growing quickly (Bjornson, 2013).
Challenging Problem or Question
The project is framed by a meaningful problem to solve or a question to answer, at the
appropriate level of challenge (M3U4A2, 2015). Which food will grow the most molds? The
least? Why? Which environment has the greatest mold growth?
Materials
 Plastic zip-top bags
 Knife
 Labeling tape and marker
 Two or three types of food (such as greens, bread, meat, cheese, fruit, etc.)
 Notebook and pen or pencil
 Spray bottle
 Water
 Cooking pan, toaster oven, oven or other cooking device.
Procedure
1. Select some different foods to test.
2. You will need 9 samples for each type of food.

2. 3. Take 3 samples of each type of food and cook them. How might this condition affect how
mold grows on the food?
4. Place each sample into a plastic zip-top bag and seal it. Label each bag appropriately with
type of food, the conditions, and environment.
5. Take 3 samples of each type of food and spray lightly with water. Do you think the wet
samples will grow mold more quickly or slowly? Why? (Bjornson, 2013).
Student Voice & Choice
Students make some decisions about the project, including how they work and what they
create (M3U4A2, 2015). Wet samples will grow the most molds, while cooked samples will
grow the least mold. Samples left in the sun will grow the most molds, while refrigerated
samples will grow the least mold. Why? (Bjornson, 2013). Molds need water and nutrients to
grow, so wet, uncooked samples will provide the most nourishment to many types of molds.
Cooking food often denatures (destroys) many proteins and nutrients in food and makes it
harder for mold to use the nutrients for growth. Mold also thrives in warm environments, so
the samples left in the sun will mold first. Refrigeration prevents cell activity in many living
things like fungi and bacteria, which is why foods typically last longer in the refrigerator
(Bjornson, 2013).

3. References
http://bie.org/about/what_pbl
http://www.education.com/science-fair/article/environment-affects-food-mold-spoil/