California Agriculture in the Classroom

High-Tech Food

Grade Level(s)

6 - 8

Estimated Time

45

Purpose

This lesson plan introduces the high-tech aspects of agricultural production and explores the related careers.

Materials

Essential Files (maps, charts, pictures, or documents)

Essential Links

Vocabulary

DNA: deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes; the carrier of genetic information

genetically modified food: genetically modified (GM) foods are foods derived from organisms whose genetic material (DNA) has been modified in a way that does not occur through a normal reproductive process (e.g., through the introduction of a gene from a different organism)

Did you know? (Ag Facts)

Background - Agricultural Connections

There really is science in your shopping cart! If we abide by the familiar saying “you are what you eat,” it is understandable that people may be concerned with the incredible advances in food science technology and their possible impacts on human health. For example, in recent years high-tech scientific processes such as genetic modification, irradiation, and cloning have all been used to increase the safety of the food supply, create foods that are more appealing to eat and easier to produce, and increase crop yields. This article will summarize a few hot topics in food science, address what is currently known about the safety of these processes, and present resources on the subject to use with your students.

What are genetically modified foods? Genetically modified (also referred to as GM) foods are produced from sources whose genetic makeup has been altered through genetic engineering processes such as recombinant DNA or gene splicing. While this technology is relatively new, if viewed in a historical context, people have been selecting desirable plant and animal DNA through traditional selective breeding processes for centuries. All plant and animal breeding that is selective—choosing particular parent stock, plant or animal, and cross-fertilizing (naturally or artificially) to produce offspring with desired traits of the parents—is, in actuality, low-tech “genetic engineering.” While it is not normally thought of as scientific technology, it provides the foundation for how we have selected the desired traits for our food—color, taste, size, yield—for centuries. Even though humans did not have the capacity to isolate DNA until recently, by choosing certain individuals for breeding, they were in fact selecting the DNA that would be replicated. In contrast, newer biotechnology in food production uses gene splicing, recombinant DNA, cloning, or other techniques to produce the desired plant or animal product. With gene splicing and recombinant DNA directly modifying only certain parts of the organisms’ DNA, it is possible to produce a more consistent product than would be possible using simpler forms of genetic manipulation or selective breeding. The first genetically modified whole food product, a tomato that could be shipped vine-ripened without rotting rapidly, went on the market in 1994. Today, the top three genetically modified crops in the United States are soybeans, corn, and cotton. Crops are modified not only for better taste and decreased spoilage, but also for resistance to disease and insects, and tolerance to certain herbicides or pesticides. Manipulating DNA through genetic modification also allows genes from animals to be inserted into plant genomes— an example would be inserting the “antifreeze protein” gene from the Arctic flounder into a tomato’s genome to produce a tomato that freezes and thaws better than the traditional tomato. What results is an example of a transgenic plant. Another successful example is the insertion of bacterial DNA that kills certain insects into a plant’s genome, thus making the plants pest-resistant.

Genetic modification is not limited to the addition of DNA to an organism. Scientists are also genetically modifying the DNA of certain plants to remove or to silence parts of its DNA that cause allergic reactions or gastric distress to those who consume the plants. For example, through gene silencing, researchers were able to alter soybeans so they did not produce a protein called P34, which causes an allergic reaction in 75 percent of the people allergic to soybeans (Bren 2003). Work is continuing on this technique with soybeans, because there are up to 15 different proteins in soybeans that cause allergic reactions. To be totally effective, scientists will have to determine which of the additional 14 proteins cause allergic reactions and find ways to knock out those proteins as well; it is hoped that within a few years they will be successful. It is estimated that between 70 and 75 percent of all processed foods now available in U.S. grocery stores may contain ingredients from genetically modified plants. Additionally, it must be remembered that genetic modification is not limited to whole foods—ingredients may also be engineered.

Today, foods such as bread, cereal, hot dogs, pizza, and soda contain genetically engineered ingredients. Genetically modified foods are not required in the United States to carry special labels, unless their content is significantly different from other products of the same type of food (such as decreased nutritional value, added allergen components, and so on). U.S. law requires foods to be labeled with information concerning their material and its processing, not the method by which a plant is developed by a breeder. For example, orange juice that is labeled as “fresh orange juice” cannot have been subjected to heat or chemical processing or processed into concentrate at any time before sale; the word fresh is considered to refer to the material (contents). Alternatively, if the oranges from which that same orange juice was made were the product of a hybrid cross-fertilization procedure, the orange juice is not required to be labeled “hybrid orange juice” because “hybrid” refers not to the contents of the orange juice, but to the method by which the oranges themselves were created. In actuality, almost every product we eat would require special labeling as to the method that was used to produce it if labeling laws extended beyond materials (contents) to include production methods.

There are several concerns raised about genetically modified foods. Transgenic plants have received much more attention than transgenic animals, partly because most transgenic animals are usually used for pharmaceutical or research purposes rather than for food. Concerns about genetically modified foods fall into several categories:

Interest Approach – Engagement

  1. Begin introducing the lesson by asking the following questions and holding a class discussion:
    • How do science and technology solve agricultural problems?
    • What role does the consumer have in determining what items are found on supermarket shelves?
    • Are more career opportunities related to being a food producer or a consumer? Explain your answer.
  2. In this lesson students will learn the answers to these questions and begin to understand the high-tech nature of our food production and the careers related to it.

Procedures

Activity 1:

  1. Assign each pair or small group of students one of the products listed on the Agricultural Science and Technology Worksheet. You may want to provide each group with a picture of the product they have been assigned. Alternatively, a “real” food or nonfood product on the list may be used to add interest.
  2. Review the Science in Your Shopping Cart PowerPoint presentation, slides 1-5, and discuss the scientific changes that are sometimes used to change particular crops, animals, and resulting foods.
  3. Ask each pair/group to write down, on their Agricultural Science and Technology Worksheet, the scientific changes they think have been applied to the development of the product they have been given (there may be more than one).
  4. View with your students the video Science in Your Shopping Cart (streams from the Internet or purchase the DVD). Ask students to write down the actual scientific changes all the products shown in the video have undergone to get that product to the consumer.
  5. After viewing the video, ask students if they guessed the scientific changes correctly. Students will notice that not all the products were shown in the video. Provide each group with a copy of the Science in Your Shopping Cart booklet (order or view online) to complete the worksheet.
  6. Show students slides 6 and 7 in the PowerPoint presentation for a few other examples of food science.

Activity 2:

  1. Technology is the application of science. To further demonstrate science and technology used in agriculture, view with students the video/DVD Modern Marvels: Harvesting Technology (order online from the History Channel).
  2. Students can then complete the last column on the Agricultural Science and Technology Worksheet. This video details harvesting technology for the following: GPS/GIS wheat, cotton, rice, sugar beets, tomatoes, walnuts, olives, lettuce, grapes, and oranges.

Activity 3:

  1. Review with students the Concerns About Food Science, the last five slides in the Science in Your Shopping Cart PowerPoint presentation. Here are some questions for discussion:
    • Are the food products safe to eat?
    • Do the benefits of GMO foods outweigh the risks?
    • What is on the horizon in food science?
    • What is left to invent?
    • What are some career opportunities in the area of food science and food technology?
    • How many people have really made a loaf of bread or a gallon of milk?
    • From farm to fork: how much science is in your shopping cart?

Concept Elaboration and Evaluation

After conducting these activities, review and summarize the following key concepts:

Suggested Companion Resources

Author(s)

Debra Spielmaker

Organization Affiliation

National Agriculture in the Classroom