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 plants have been genetically
engineered and which food products contain genetically modified ingredients.
Students present their findings in a formal lab report.
Students work together to present evidence – 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
LS2
LS2
LS3
LS4
(9-11)
(9-11)
(9-11)
(9-11)
(9-11)
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
2b
3b
5b
6a
9b
See appendicies for full text of GSEs.
See appendicies for full text of benchmarks.
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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:
Students will be able:
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.
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
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results.
Other evidence of learning (quizzes, tests, prompts, observations, lab reports,
work samples, etc.)
Formative: Lab notebook from each student including 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 report from each student including 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
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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?
http://www.pbs.org/wgbh/harvest/engineer/ (optional)
http://www.pbs.org/wgbh/harvest/etc/video.html (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?
http://www.dnai.org/b/index.html (optional - 2D animation on transformation)
2. What are restriction enzymes and how are they used for genetic modification?
http://www.dnai.org/b/index.html (optional - 2D and 3D animations on restriction enzymes)
3. How are plants modified? http://www.pbs.org/wgbh/harvest/engineer/ (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? http://www.dnai.org/b/index.html (3D video on PCR, interviews
with Kerry Mullis).
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3. How does PCR work? http://www.dnai.org/b/index.html (2D animation)
4. How can the size of DNA be determined?
5. What is electrophoresis? http://www.dnai.org/b/index.html
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, precast 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?
http://www.dnai.org/teacherguide/guide.html (optional - paper activity to demonstrate gel
electrophoresis).
http://www.dnai.org/b/index.html (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?
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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.
2.
3.
4.
5.
6.
Where in the cell is DNA located?
Why do we grind up plant tissue or food?
Why does the buffer contain detergent?
Why do we boil the samples?
How does ethanol precipitate DNA?
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.
http://bioinformatics.dnalc.org/gmo/animation/index.html
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.
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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?
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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: http://www.pbs.org/wgbh/harvest/
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.
DNA Learning Center – DNA Interactive: http://www.dnai.org/ Web resource
for restriction enzymes, gel electrophoresis, PCR.
Bioinformatics - http://bioinformatics.dnalc.org/gmo/animation/index.html
Identify the sequence and size of PCR product produced in the “Detecting GM
foods by PCR” laboratory exercise.
For further research:
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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.
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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?
d. The human species has a major impact on other species in many ways: reducing the
amount of the earth's surface available to those other species, interfering with their food
sources, changing the temperature and chemical composition of their habitats, introducing
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foreign species into their ecosystems, and altering organisms directly through selective
breeding and genetic engineering.
5C Cells
d. The genetic information encoded in DNA molecules provides instructions for assembling
protein molecules. The code used is virtually the same for all life forms. Before a cell
divides, the instructions are duplicated so that each of the two new cells gets all the
necessary information for carrying on.
5D Interdependence of Life
c. Human beings are part of the earth's ecosystems. Human activities can, deliberately or
inadvertently, alter the equilibrium in ecosystems.
8A Agriculture
a. New varieties of farm plants and animals have been engineered by manipulating their
genetic instructions to produce new characteristics.
c. Agricultural technology requires tradeoffs between increased production and
environmental harm and between efficient production and social values. In the past
century, agricultural technology led to a huge shift of population from farms to cities and
a great change in how people live and work.
12A Values and Attitudes
a. Know why curiosity, honesty, openness, and skepticism are so highly regarded in science
and how they are incorporated into the way science is carried out; exhibit those traits in
their own lives and value them in others.
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