TITLE: CHARTING MOLD GROWTH
AUTHOR: MELODIE HILL, LEWIS ARRIOLA ELEMEN., CORTEZ, CO
GRADE LEVEL/SUBJECT: Appropriate for grades 2-6
OVERVIEW: Micro-organisms live, grow and reproduce all
around us. They are both detrimental and helpful. This
activity is designed to show students that they are all
around, and that their population growth can be charted
based on food supply.
OBJECTIVE(s): Students will be able to:
1. Identify sources of micro-organisms (air, water, etc.)
2. Show micro-organism growth on an available food supply.
3. Chart micro-organism growth and decline as the food
supply runs out.
4. Describe factors that inhibit micro-organism growth
(cold, sunshine, sterilization, etc.)
5. Describe ways that micro-organisms are used
successfully.
RESOURCES:Small container or jar, tape, bread, boiling water
to sterilize, access to refrigerator, graph paper, yogurt,
cheese, yeast bread slices, hand lenses.Student resources:
pencil or writing utensil.
ACTIVITIES:
1. Using tape, label a container, (Jar, small petri-dish,
etc.) with the students name. Select some to sterilize
with boiling water. Select some to leave as is.
2. Place half a piece of bread in each jar. Seal with
tape. Label with variable being tested. Place some
outside in the sunshine, place some in the
refrigerator, leave some as is.
3. Cut Graph paper circles and tape on bottom of petri
dish. Count number of squares visible each day.
Numbers should decrease. Observe over several days
with hand lens. As food supply runs out, mold will
begin to die off itself. Number of visible squares
will remain the same, or increase. Have students keep
a graph of several days growth. Mark points of
increase, stabilization and decrease.
4. Compare class results. Cultures grown in refrigeration
and under sunlight will have little growth. Cultures
grown under sterilization will have little or no
growth. Those left as is will have abundant growth.
5. Bring bread dough, yeast, yogurt, etc. Explain that
micro-organism growth has productive side effects.
Parent volunteers can help you make yeast bread, or
yogurt with the class
Click here to return to OFCN's Academy Curricular Exchange
Click here to return to OFCN's Academy
Click here to return to OFCN's Main Menu
John Kurilecjmk@ofcn.org