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Chocolate Flavored Cherries
From Dining on DNA: an Exploration of Food Biotechnology by Montana Sate University Extension Service
Modified by Kirstin Bittel and Rachel Hughes

Time: 1 class period
Preparation Time: 10-15 minutes photocopying handouts
Materials:

1 copy of Background page per student
1 copy of Procedures page per group
1 copy of DNA page containing

Cacao DNA (linear)
Plasmid DNA (circular)

Restriction enzyme (scissors)
Ligase (tape)

 


Abstract
During this lesson students are introduced to the process of recombinant DNA through the imaginary creation of chocolate flavored cherries. Students use a paper simulation to model using restriction enzymes to remove a gene from one plant and insert it into another.

Objectives
Students will be able to:-
1. Identify start and stop sequences in DNA.
2. Model using restriction enzyme and ligase to remove sections of DNA and reattach them.

National Science Education Standard
Content Area C – The Molecular Basis of Heredity
- In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a larger polymer formed from subunits of four kinds (A, G, C, and T). The chemical and structural properties of DNA explain how the genetic information that underlies heredity is both encoded in genes (as a string of letters) and as replicated (by a templating mechanism). Each DNA molecule in a cell forms a single gene.

Content Area C – The Interdependence of Organisms
- Human beings live within the world’s ecosystem. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption.

Teacher Background
In recombinant DNA, scientists use restriction enzymes to cut DNA into its parts. New genes can be added to sections or specific genes can be removed altogether.


Related and Resource Websites

 

 

Activity
Engage (How can we use our knowledge of DNA to make specific foods taste better?)
1. Tell students, “A large candy company has hired your laboratory to conduct an important project. Consumer surveys indicate that people love the combined flavors of chocolate and cherry, so ACME Candy Company is attempting to develop a new product, chocolate flavored cherries. They want to be the first to put these delicious cherries on the market. You are the laboratory technician who has been hired to insert the gene for chocolate flavor into cherry DNA so that it bears a fruit with chocolate flavor. The “big shot” at your lab has already isolated a gene in chocolate that is responsible for its flavor. Your job is to follow the procedures provided in order to insert the gene responsible for chocolate flavor into vector DNA so that the gene can be carried into the cherry.
2. Give students an opportunity to read the background information provided (approximately 5 minutes).
3. Have a brief discussion with the class where they brainstorm possible ways they could remove a section of DNA from one gene and insert it into Plasmid DNA. What things would they need to consider before cutting the desired gene out? (start and stop sequences) What things do they need to consider before inserting the new gene? (base pairs)
4. Give students the Procedures page and DNA page. Allow time for students to complete the procedures.
5. Ask students the following questions:
- What is your least favorite food?
- What specific quality about that food do you dislike?
- What other food could you use to help modify your food?
6. Have students write up the laboratory procedures they would use, in detail, to modify their least favorite food. They should begin with extracting the desired trait from the first organism and end with how the “new” gene is recombined into the DNA of their least favorite food. (This can be a homework piece)
7. Walk around the room during the first part of the lab to check to make sure that students are following the laboratory procedures and can correctly remove the desired gene from the cocoa plant and insert it into the vector DNA.
8. After students have finished their procedures, check to be sure that all steps are accounted for and are in the correct order.
9. Revisit the question used to open the class. How can we use our knowledge of DNA to make specific foods taste better? How can this technology be applied to other areas? Give students 5 minutes to write their ideas and take the remaining class time to discuss ideas.

Homework
(Optional) Survey 25 people to see if they would buy your “new” product.

Embedded Assessment


PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:


an
NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award

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Supported by NIEHS grant # ES06694


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Last update: November 10, 2009
  Page Content: Rachel Hughes
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