Michigan Geographic Alliance
Environmental Science
Material Type:
Activity/Lab, Lesson Plan
Middle School
Environment, Environmental, MEECS
Creative Commons Attribution Non-Commercial

Education Standards

Ecosystems and Biodiversity Lesson 2 Extension : Sandwich Super Sleuths


In this activity students will identify where the ingredients in a tomato and cheese sandwich originated. They will trace a food item from its place as a sandwich ingredient to where it was originally grown. Students then suggest ways that people can minimize their impact on ecosystems and biodiversity by making informed decisions about food choices.

Lesson Overview

Lesson adapted, with permission, from the ”Sandwich Super Sleuths” lesson, written by the Organic Trade Association (OTA). For more information about the organization, and for other related lessons, visit the following site: http://www.ota. com/organic_and_you/education.html.

In this activity students will identify where the ingredients in a tomato and cheese sandwich originated. They will trace a food item from its place as a sandwich ingredient to where it was originally grown. Students then suggest ways that people can minimize their impact on ecosystems and biodiversity by making informed decisions about food choices.

Subject/Target Grade Level
Science and Social Studies/UpperElementary & Middle School (4-6)

45 minutes – Classroom setting

per class
• tomatoes
• packages of sliced cheese
• loaf of bread
• jar of mustard
per small group
• one large sheet of chart paper
• markers and pencils
per student
• journal or notebook
• pen or pencil
• bag lunch (optional)


Students will be able to:
1. Trace the origin of the food they eat.
2. Identify examples of ways that food items may negatively impact ecosystems and biodiversity.
3. Suggest ways that consumers can minimize their impact on ecosystems and biodiversity by making informed decisions about food choices.

Advance Preparation

You may wish to make tomato and cheese sandwiches for each group, or give students the opportunity to make their own. If you choose to not make sandwiches, bring in the sandwich ingredients as visual aids.

Background Information

Students may not know the origin of the food they eat. They may not know more than it comes in packages or containers from the grocery store shelf. They may not connect food to farms, ranches, the ocean, lakes, or rivers. Most children do not even think about how the food is prepared for sale and transported. The point of this activity is to encourage students to think about where their food comes from, how it was grown and processed, the important role that agriculture plays in their lives, and how food production may negatively impact ecosystems and biodiversity. In today’s society, with more and more people living in urban areas, students are farther removed from the source of their food than past generations.
Consider a big, juicy apple sitting on your desk. Where did it come from and how did it get there? Maybe you bought it at your local grocery store, but where is the apple tree that produced it? Perhaps the apple was grown in a nearby orchard, or in another state or even another country. While Michigan has a large apple-growing industry, many of the apples in our stores come from the state of Washington or other countries such as Chile or New Zealand (especially out of season). How was it grown? How did the grower control pests? How much water was used for crop irrigation? How was it harvested, and by whom? Was it stored before shipping? How was it shipped? What amount of fossil fuels was burned to produce this apple and bring it to you? These are the kinds of questions your students will think about as they analyze a tomato and cheese sandwich.
The goal of this activity is to elicit from students their current ideas about their food and where it comes from – to discover how many students already know how food is grown, transported, stored, packaged, and prepared. This will give youa baseline understanding of your students’ current level of knowledge of food and food production.


The tomato and cheese sandwich could be replaced with different ingredients (e.g., peanut butter and jelly). Non-diary cheese substitutes are available in most grocery stores


1. Divide students into a minimum of three groups. One group will be the tomato group, another will be the cheese group, and a third will be the bread group. A fourth option is to have a mustard group.
2. Ask each group to brainstorm the origins of their group’s food item. Suggest that each group draw a picture of the food and then diagram where it came from. Encourage students to use as much detail as possible as they describe how the food is grown and processed. Stimulate their thinking with questions such as:
• What is the main ingredient in your food item?
• What else can be made from this item?
• What does it look like in its unprocessed form?
• Where in the country (or world) does it grow?
• How was the item harvested?
• How did it become what it is now?
• How did it get from its original source to you?
3. Circulate among the groups. If students need help, encourage them to consider where the food was grown, who raised and/or harvested it, who prepared it and packaged it, and how it was stored and transported.
4. Ask students to consider how the various steps involved in producing the food item may havenegatively impacted ecosystems and biodiversity [For example, pesticides used on crops may directly or indirectly affect wildlife and even people]. Students may add illustrations to their diagrams showing the impacts to ecosystems and wildlife.
5. After students have finished their diagrams, invite each group to share its drawing with the class.
6. Lead a discussion relating to the diagrams, using the following questions:
• What steps were involved in bringing these items to the market? [e.g., production, transportation, processing, distribution, retail]
• Where did the food items originate? [usually on farms, perhaps in different parts of the country]
• What do these food items have in common? [e.g., they were grown on farms, similar type packaging, were transported on trucks, etc.]
• Where are they in the “food chain”? [producers, consumers, decomposers]
• In what ways are ecosystems and wildlife negatively impacted? [e.g. pollution from pesticides and fertilizers, erosion, use of water for irrigation and processing, pollution caused by burning fossil fuels, etc.]
6. Tying it all together. Once students are aware that all of the food items they diagrammed are grown or raised from the Earth, engage them in a discussion of how some food choices may impact the ecosystems and biodiversity (and be healthier) more than others. For example, consider how some of the following factors might impact the environment (and our health).
• How the food was grown (amount of chemical pesticides, etc.)
• Amount of processing (refined sugar and flour vs. whole grains, etc.)
• Amount of packaging (answers vary, some products have no packaging)
• Type of packaging (biodegradable or recyclable vs. non-recyclable)
• How far away the food was grown.


• Repeat this activity, this time having students select one item from their own lunch. Ask each student to diagram the steps involved in bringing the lunch food item from the field to the lunchroom.
• Have students list three things that people can do to make food choices that minimizes their impact on ecosystems and biodiversity [e.g., choose food that is: grown with fewer or no synthetic pesticides and fertilizers, less processed, has little or no packaging, or is locally produced]


Have students bring in clean, empty food packages (like cereal boxes), and then compare them based on factors such as the amount of packaging or how far away the food was produced.

Additional Resources

Creative Change Educational Solutions
Creative Change, of Ypsilanti, MI works with schools to develop courses and custom curriculum packages built around an extensive library of curricula, units, and activities. One of their content specialties deals with food systems that involve how the foods we eat come to our tables through a complex global system that has developed over centuries. How we eat has serious, and often hidden, implications for our economy, the environment, and our health.,retrieved August 30, 2005.

Project Food, Land & People (FLP)
FLP promotes approaches to learning to help people better understand the interrelationships among agriculture, the environment, and people of the world. FLP is the publisher of Resources for Learning (1998), a collection of 55 Pre-K through 12th grade lesson plans for use in either a formal or non-formal education setting. http://www. (available August 30, 2005)

The Food Project
The Food Project is a launching pad for ideas about youth and adults partnering to create social change through sustainable agriculture. Their mission is to grow a thoughtful and productive community of youth and adults from diverse backgrounds who work together to build a sustainable food system. (available August30, 2005)

Lesson Plans, Redefining Progress
These lesson plans, developed for use in elementary and middle school classrooms, have been created by Redefining Progress and the Earth Day Network. The lessons address a variety of topics, including how our everyday food choices impact the environment. (availableAugust 30, 2005).

Waste-Free Lunches
The average school-aged child, who takes a lunch to school, generates an estimated 67 pounds of trash per year. This web site is just one of many offering ideas and suggestions for participating in or starting a “waste-free” lunch program at your school or workplace, with the goal of reducing the amount of trash generated from food packaging. (available September 8, 2005)

In Print
Coblyn, Sara. (2001). French Fries and the Food System. Lincoln, MA: The Food Project.
This agricultural curriculum for grades 5-12 features original lessons written and developed by The Food Project’s growers and educators. Organized by season, the material teaches youth how to develop a deep understanding of and appreciation for the land and local food systems. Lessons can be done both indoors and outdoors and can be easily adapted by instructors working in school-based plots, urban food lots, and environmental education programs.
Council for Environmental Education. (1992). Project WILD: K-12 Activity Guide. Bethesda, MD: Council for Environmental Education. (
In the lesson “What Did Your Lunch Cost Wildlife,” students consider the origin of the food they eat and the impact its production may have on the environment. Students then apply this knowledge to planning their lunch.