ARISE

Teaching Unit Template

Title of Unit/Module
Genetically Modified Foods
Developed by:
ARISE Planning Team
Appropriate Course(s)/Grade(s):
Grades 9-12
Brief Summary of the Unit
Students learn about genetic modification and techniques scientists use to manipulate and study DNA. Using the techniques they’ve learned, students develop and test a hypothesis on how to find a transgene in plants and food products. Specifically, they isolate DNA from various plant and food sources and perform PCR for the promoter to an herbicide resistance gene. Amplified DNA is run on agarose gels to visualize the DNA and interpret which plantshave been genetically engineered and which food products contain genetically modified ingredients. Students present their findings in a formal lab report.
Students work together to presentevidence – based on assigned readings - to support an assigned role and viewpoint, either for or against genetic modification.
Students write a letter to their congressman or congresswoman supporting their opinion either for or against GM foods.
Grade Span Expectations
(possible GSEs)
LS1 (9-11) 2b
LS2 (9-11) 3b
LS2 (9-11) 5b
LS3 (9-11) 6a
LS4 (9-11) 9b
See appendicies for full text of GSEs. / Content Standards
(possible standards from Benchmarks for Science Literacy)
1B Scientific Inquiry a
1C Scientific Enterprise c
3A Technology and Science a
3B Design and Systems d
3C Issues in Technololgy a, c, d
5C Cells c, d
5D Interdependence of Life c
8A Agriculture a,c
12A Values and Attitudes a
See appendicies for full text of benchmarks.
Prior Knowledge:
Students should have a basic understanding of heredity, Mendelian genetics, and the structure and function of DNA as a molecule and unit of inheritance.
Also, students must have an understanding of elementary laboratory safety skills of procedures.
DESIRED RESULTS
What essential questions will be considered?
How do scientists manipulate DNA and the genome of an organism?
What ethical issues arise from genomic manipulation? What are the societal implications?
Students will know:
The history of genetic modification in plants.
How restriction enzymes cut DNA in a sequence-specific manner.
How gel electrophoresis separates nucleic acids based on size and charge.
How Polymerase Chain Reaction amplifies DNA fragments.
Have a new understanding of what we are eating and how that food is produced.
How to read an article with scientific content for bias to obtain information.
How to incorporate multiple sources of information or data on a topic into a coherent argument on a scientific and ethical issue. / Students will be able:
To form a testable hypothesis based upon observation.
To extract DNA, set up PCR reaction, and run the resulting samples on a gel.
To analyze their bands on the gel to determine if their PCR results were what they had expected, and how this data refutes or supports their hypothesis.
ASSESSMENT
Performance tasks
What will the students produce to provide evidence of understandings and skills learned?
Students will develop and orally present arguments to support their assigned opinions – either for or against GM foods.
Students will isolate DNA, set up PCR reactions, run agarose gels and interpret results.
Other evidence of learning (quizzes, tests, prompts, observations, lab reports, work samples, etc.)
Formative: Lab notebook from each studentincluding introduction, hypothesis, methods, results, data, including gel image, conclusions and discussion.
Written questions and potential hypotheses for the lab exercise
Reading Comprehension worksheet from each student
Participation in small group discussions and class brainstorming sessions
Summative: Lab reportfrom each studentincluding introduction, hypothesis, methods, results, data, including gel image, conclusions and discussion.
In-class presentations supporting their assigned role and opinion.
In class writing assignment to their congressman or congresswoman supporting their opinion either for or against GM foods.
Student Self-assessment and Reflection:
LEARNING EXPERIENCES AND INSTRUCTION
Features of Inquiry* / How is this feature included in the unit?
1, Formulating questions and hypothesizing / From observations students will work together to formulate a testable hypothesis
2. Planning and Critiquing of Investigations / After performing the experiment students will read articles and discuss the results in relation to their own results
3. Conducting Investigations / Students will perform experiments to address their specific hypothesis in a logical manner with appropriate controls
4. Developing and Evaluating Explanations / When interpreting the results of their experiments students will evaluate the validity of their hypothesis, making new theories, asking further questions, and determining areas of error and problems

* See the NECAP Schema for Assessing Scientific Inquiry for 13 possible tasks for the 4 Broad Areas of Inquiry

Instructional Sequence/Calendar – see separate page for calendar
**Note that wildtype and Roundup Ready Soybean seeds should be planted three weeks prior to the start of the unit. If possible, plan Day 1 to fall on a Tuesday.
DAY 1 (Tuesday) Introduction to unit.
1. What is genetic modification?
2. Does genetic modification only happen in plants?
3. How long has genetic modification been taking place? What is the history of genetic modification?
4. How is modern technology used to genetically modify organisms?
(optional)
(optional)
5. What are some reasons for genetic modification? Why would we want something to be genetically modified?
Homework: List three questions that you have regarding GM foods.
DAY 2 (Wednesday) How do scientists insert genes into organisms? Focus on techniques.
1. How do scientists genetically modify organisms? Bacteria? Mouse? (optional - 2D animation on transformation)
2. What are restriction enzymes and how are they used for genetic modification?
(optional - 2D and 3D animations on restriction enzymes)
3. How are plants modified? (optional)
4. How would you modify plants to make crops more accessible? How would you want them to be different?
5. Do farmers want crops that grow faster? Produce more food? Produce an insecticide? Resist a weed killer?
6. What is Roundup and how does it work?
7. How do plants resist Roundup?
8. Does being GM affect the plant? What happens when we spray wildtype and Roundup Ready (RR) plants with Roundup?
Lab Exercises:
Restriction Enzyme paper lab
Spray wildtype and RR plants with Roundup
Homework: Provide lab handouts / protocol for students to read for Day 6. This may also be distributed on Day 5 or in class on Day 6.
DAY 3 (Thursday) Continue focus on techniques. PCR & Intro to Gel Electrophoresis
1. What happened to plants sprayed with Roundup?
2. What is PCR? Who discovered it? (3D video on PCR, interviews with Kerry Mullis).
3. How does PCR work? (2D animation)
4. How can the size of DNA be determined?
5. What is electrophoresis?
6. Describe cool-aid electrophoresis exercise to be performed on Day 4.
7. Assign roles and opinions for research, small group discussion and presentation. This can be done anytime between days 3-7. Small group discussions begin on Day 8.
The class should be divided into 5 groups. Each group will be assigned a role and opinion as follows:
Organic farmer – against GM foods
Environmental activist – against GM foods
Agricultural Minister of developing country – for GM foods
Agrobusiness – for GM foods
Consumer – for or against GM foods
Homework: This assignment is due on Day 8. Each group receives two papers supporting their assigned opinion. Additionally, all students will receive a paper that represents both sides of the GM debate. Based on information presented in the papers, students should come up with 5 points to support their position. Students should consider the source of the reading and bias of the contributing authors. Who wrote the article? Why did they write this? What is their bias? What does the writer want you to get out of this?
The following questions can be considered:
1. Do GM foods hurt us in any way?
2. Can GM crops have any adverse effects on the environment?
3. Can GM crops get out into the wild?
4. What kinds of benefits do GM crops provide?
5. Should companies tell you if they use GM crops in food products?
6. How are GM crops and foods regulated in the US? In other countries?
7. How has the media reported on GM food?
8. How does society decide whether to use a new technology?
DAY 4 (Friday) How does electrophoresis work? Note that demo gel for the cool-aid electrophoresis should be prepared and pre-run prior to the class. Depending on time, pre-cast gels for student practice loading may also be needed.
1. What happened to plants sprayed with Roundup?
2. What is electrophoresis, how does it work and what can we learn from it?
(optional - paper activity to demonstrate gel electrophoresis).
(optional - 2D animation of gel electrophoresis)
3. What is a testable hypothesis regarding electrophoresis of cool-aid.
Lab exercise: Demonstrate cool-aid electrophoresis. Students will practice loading samples into gels.
Day 5 (Monday) How can we find a transgene in Roundup Ready plants and GM food?
1. What is a hypothesis? (This should be review.)
2. What is a testable hypothesis?
3. Using the techniques we just learned about (restriction enzymes, PCR and gel electrophoresis), how could we find the RR gene in plants or foods?
Sample hypothesis: Jiffy corn muffin mix will contain GM ingredients. I can use PCR and gel electrophoresis to determine if the corn meal mix contains DNA that allows it grow in the presence of the herbicide Round Up.
4. What foods would we want to study to determine if they contain the RR gene?
If not already done, assign roles and opinions for research, small group discussion and presentation. Small group discussions begin on Day 8. (See Day 3 for more details).
Homework: Bring in dry corn or soy food product. Examples include: corn and tortilla chips, corn muffin mix, artificial bacon bits, granola and energy bars, pet food. Additionally, teachers will have GM foods used on Day 1.
If not done earlier in the unit, provide lab handouts / protocol for students to read for Day 6. This may also be distributed in class on Day 6.
DAY 6 (Tuesday)How can we isolate DNA from plant and food material?
1. Where in the cell is DNA located?
2. Why do we grind up plant tissue or food?
3. Why does the buffer contain detergent?
4. Why do we boil the samples?
5. How does ethanol precipitate DNA?
6. Why is RNase present in the buffer?
Homework: Tomorrow we will set up PCR reactions. Predict whether the product you are working with is GM or non GM. Predict the results of the PCR reactions if the food or plant you are working with is modified. How does this compare to predicted results if the material is not modified? Draw an image of a gel for both GM and non GM foods.
Student lab reports on this multi-day lab are due on Day 14.
Day 7 (Wednesday) How do we set up PCR reactions to test if a food product is GM or non GM?
Discuss format of small groups. Samples for PCR should be sent to Brown.
Optional - Bioinformatics exercise can be introduced to determine predicted size of PCR product.

1. Why are two PCR reactions set up for each DNA sample?
2. What components must be included in the PCR tubes for the reaction to work?
3. What are the predicted results for GM and non GM foods? Review of homework.
Homework: Student lab reports on this multi-day lab are due on Day 14.
Prepare students for Day 8. Homework assigned earlier in the unit is due tomorrow (Day 8). Based on information presented in their assigned papers, students should come up with 5 points to support their position. Students should also consider the source of the reading and bias of the contributing authors. Who wrote the article? Why did they write this? What is their bias? What does the writer want you to get out of this?
Day 8 (Thursday) Collaborative work. Students come up with arguments to support their assigned opinions.
1. What facts, pieces of evidence and data support each point?
2. Are all these pieces of information scientifically accurate? What is the source of the evidence used to support each point? What errors or problems can be found with a particular experiment or line of reasoning?
Homework: Each student needs to represent a different point of their group’s argument which they will present on day 9.
Day 9 (Friday) Presentations
Groups present their arguments. Each student should represent one point of their argument
After group 1 presents, groups 2-5 will submit a question in writing to group 1. The teacher will also present group 1 with a question. This format will be followed for all groups.
Homework: Each student will prepare a response to their question.
Day 10 (Monday) Presentations: Response to questions
Each student will read the question posed to them on Day 9 and present their answer.
Day 11 (Tuesday) Analysis of PCR products
1. What is the purpose of the DNA ladder?
2. Why are the PCR products loaded at the “negative” end of the gel?
3. What are the predicted results for GM and non GM foods and plants?
4. View gels and photograph results
Homework: Student lab reports on this multi-day lab are due on Day 14.
Day 12 (Wednesday) Analysis of results and discussion
1. From which food and plant samples was DNA isolated? What is the size of the tubulin PCR product?
2. Which food and plant samples were positive for the presence of the Roundup Ready gene? What is the size of the RR gene PCR product?
3. Where could or did things go wrong? What can be done in future to rectify this problem?
Homework: Student lab reports on this multi-day lab are due on Day 14.
Day 13 (Thursday) In class writing assignment
Write a letter to your congressman or congresswoman supporting your opinion either pro or con GM foods. Use information from readings, group discussions or lab activities to support your opinion.
Technology and Other Resources Needed
Plants, seeds, and foods from genetically modified and not modified organisms for samples.
Equipment and reagents for DNA isolation, PCR amplification and gel electrophoresis.
Articles for group discussions on assigned roles and opinions.

Web resources: Listed here and throughout the unit and lesson plan.

Harvest of Fear:

Key arguments pro and con GM foods, flash animation of how to genetically modify a plant, a look at GM foods currently under production, links to pro- and anti-GM websites, video on GM salmon.

DNALearningCenter – DNA Interactive: Web resource for restriction enzymes, gel electrophoresis, PCR.

Bioinformatics - Identify the sequence and size of PCR product produced in the “Detecting GM foods by PCR” laboratory exercise.

For further research:

Appendices:

Grade Span Expectations for the Genetically Modified Foods Unit

LS1 (9-11) 2

Students demonstrate an understanding of the molecular basis for heredity by…

2b Explaining how DNA may be altered and how this affects genes/heredity (e.g. substitution, insertion, deletion)

LS2 (9-11)

Students demonstrate understanding of equilibrium in an ecosystem by…

3b Describing ways in which humans modify ecosystems and describe and predict the potential impact

LS2 (9-11)

Students will evaluate potential bias form a variety of media sources in how information is interpreted by…

5b Applying additional scientific data to develop logical arguments concerning environmental issues

LS3 (9-11)

Students will demonstrate their understanding of the degree of relationships among organisms by…

6a Using given data (diagrams, charts, narratives, etc.) and advances in technology to explain how our understanding of genetic variation has developed over time.

LS4 (9-11)

Students demonstrate an understanding of how humans are affected by environmental factors and/or heredity by…

9b Providing an explanation of how the human species impacts the environment and other organisms

Benchmarks for Science Literacy

1B Scientific Inquiry

By the end of the 12th grade, students should know that:

a. Investigations are conducted for different reasons, including to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.

C Scientific Enterprise

c. Progress in science and invention depends heavily on what else is happening in society, and history often depends on scientific and technological developments.

f. Scientists can bring information, insights, and analytical skills to bear on matters of public concern. Acting in their areas of expertise, scientists can help people understand the likely causes of events and estimate their possible effects. Outside their areas of expertise, however, scientists should enjoy no special credibility. And where their own personal, institutional, or community interests are at stake, scientists as a group can be expected to be no less biased than other groups are about their perceived interests.

3A Technology and Science

a. Technological problems often create a demand for new scientific knowledge, and new technologies make it possible for scientists to extend their research in new ways or to undertake entirely new lines of research. The very availability of new technology itself often sparks scientific advances.

3B Design and Systems

d. Risk analysis is used to minimize the likelihood of unwanted side effects of a new technology. The public perception of risk may depend, however, on psychological factors as well as scientific ones.

3C Issues in Technology

a. Social and economic forces strongly influence which technologies will be developed and used. Which will prevail is affected by many factors, such as personal values, consumer acceptance, patent laws, the availability of risk capital, the federal budget, local and national regulations, media attention, economic competition, and tax incentives.

c. In deciding on proposals to introduce new technologies or to curtail existing ones, some key questions arise concerning alternatives, risks, costs, and benefits. What alternative ways are there to achieve the same ends, and how do the alternatives compare to the plan being put forward? Who benefits and who suffers? What are the financial and social costs, do they change over time, and who bears them? What are the risks associated with using (or not using) the new technology, how serious are they, and who is in jeopardy? What human, material, and energy resources will be needed to build, install, operate, maintain, and replace the new technology, and where will they come from? How will the new technology and its waste products be disposed of and at what costs?