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        9-12

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        Using Biotechnology to Detect and Treat Disease

        In this media-rich lesson, students learn how biotechnology's techniques and tools are being used to help identify and fight disease, and examine the ethical and privacy issues associated with genetic testing.

        Lesson Summary

        Overview

        Biotechnology is a large scientific field that uses research tools from chemistry and biology to study or solve problems, including human disease. Biotechnologies may be used to study the genetic material of viruses and bacteria to determine whether a disease is caused by particular disease-producing agents. Its techniques are also used to understand how genetic factors contribute to human disease. The information gathered in research can be used to develop diagnostic tests that enable speedy detection and identification of a disease so that an appropriate treatment can be developed. It can also help doctors screen their patients' genomes (all of an organism's genes) for existing diseases or a predisposition for diseases such as cancer.

        This four-part lesson begins with a video that examines the threat and mechanism of a bird-borne viral infection (avian flu), as well as the controversial genetics work being done to help prevent future flu pandemics. Following a brief small-group discussion on the consequences and concerns associated with this research, students participate in a class discussion. During subsequent class periods, students learn about some of the tools and techniques researchers use to identify disease-causing genes, about the Human Genome Project and how biotechnicians sequence and analyze DNA, and about some of the emerging privacy and ethical concerns surrounding genetic testing and the gathering and storage of personal information. Each part or class period ends with a suggested extension activity designed to check for understanding. These may be completed during the class period if time allows, or assigned as homework. A culminating activity asks students to assess the cost and benefits of these efforts to understand the human genome and treat disease.

        Objectives

        • Describe the techniques and tools that help identify genes involved in disease
        • List biotechnology tools that help detect viral infection and genetic mutations
        • Discuss efforts to treat and prevent disease, including what is possible today and what is in development
        • Discuss and evaluate some of the ethical and privacy issues associated with genetic testing

        Grade Level: 9–12

        Suggested Time

        • Four 45-minute class periods

        Media Resources

        Materials

        Before the Lesson

        • If possible, arrange computers with Internet access so students can work in small groups.
        • Gather all materials for the small-group activities.
        • Review the concepts of and relationships between DNA, genes, proteins, chromosomes, and genetic engineering (moving genes between species or viruses). This may take 10 to 15 minutes depending on where this lesson is used in the scope and sequence of your curriculum.

        The Lesson

        Part I: Using Biotechnology to Detect Infectious Disease (45-minute period)

        1. Infectious diseases pose a threat to humans because they can pass quickly from person to person and affect a large number of people in a very short time. Influenza, or "the flu," is an infectious disease. You may have heard about avian and swine flus in the news. With the growing fear of bioterrorism and a pandemic flu, scientists are using biotechnology to develop new diagnostic tools for rapid and sensitive detection of pathogens. Biotechnology is used extensively in the study of emerging infectious diseases. To begin this lesson, show students the Genetically Engineering the Avian Flu QuickTime Video.

        Note to teacher: Before showing the video, you can explain in more detail the mechanism flu viruses use to transfer their genetic information to host cells. Hemagglutinin ("H") and neuraminidase ("N") are proteins produced inside an avian flu virus particle. Hemagglutinin helps the virus gain access to a host cell. Once inside, the virus releases strands of RNA that contain the virus’s genetic material. The RNA hijacks the host cell’s nucleus, causing the host cell to manufacture viral proteins. These proteins then assemble new virus particles. Once the new virus copies are complete, neuraminidase frees them from the host cell. New virus particles may now spread infection in this same manner to other host cells.

        2. In groups of four, have students discuss some of the consequences and concerns expressed in the video. Tell them they have 10 minutes to confer and should be ready to be called on to contribute to a class discussion.

        Have the groups discuss the following:

        • What part of Dr. Tumpey's experiment is considered "genetic engineering"?
        • Why might Dr. Tumpey's "virus engineering" be considered controversial?
        • What are the potential benefits of Dr. Tumpey's "virus engineering" approach?
        • Identify a challenge scientists might face in developing vaccines to eradicate viruses such as the flu or HIV.
        • Do you think this challenge can be or will be overcome? Why or why not?

        Next, lead a class discussion of the group discussions.

        3. Extension Activity: For homework, ask students to go online and find other diseases that are caused by viruses. Students can fill out a 3-by-5-inch card with five facts about the viral disease they researched. Post the viral fact cards in the classroom.

        Part II: Using Biotechnology to Detect Inherited Disease (45-minute period)

        4. Disease does not only occur through infection. Inherited genes that reside in chromosomes and determine how proteins are formed in the body may be faulty or otherwise damaged. Genes code for the production of proteins in all living things. Changes that occur naturally in our genes are called mutations. While mutations are responsible for the genetic variation that makes living things different from one another, some mutations may produce defective proteins that cause disease. The tools and techniques researchers use to hunt down disease-causing genes change with a deepening understanding of genomes and with integration of new technologies.

        Have students view A Family Disease QuickTime Video. This compelling story demonstrates the detective work scientists use to recognize a gene linked with breast cancer. Then show them Genetic Therapy and Breast Tumors QuickTime Video.

        Lead a class discussion of how the dark bands on the PCR gel photo in the second video are the result of making millions of copies of a mutant gene in an individual. A band's intensity reflects the average gene copy number per cell. The highlighted bands on this gel photo show an abundance of oncogenes—genes that dispose normal cells to change into cancerous tumor cells. This may lead to a higher-than-normal expression of the protein that it encodes, which would indicate increased susceptibility for breast cancer. You can project the PCR Photo JPEG Image.

        5. Then, ask students to view the Polymerase Chain Reaction Flash Interactive, which includes an animated sequence that demonstrates this important technique. While the animation features DNA from a plant source, it's important to note that the PCR process is the same regardless of the source of DNA, be it plant, human, bacteria, or other organism. Lead a summary discussion of how PCR is an automated DNA replication technique, in which small sections of the genome are recognized and copied over and over again. This provides enough of the target DNA sample to work with in the lab. Give each student the PCR Amplification Graph PDF Document, which reinforces the idea that PCR can amplify a specific DNA sequence more than a billion times in a matter of hours.

        6. Extension Activity: For homework, ask students to go online and find examples (news articles) of other uses for PCR technology in DNA fingerprinting (genetic recognition) of humans, plants, or animals.

        Part III: DNA Sequencing, Genomics, and Biomedical Applications (45-minute period)

        7. Lead a short discussion of what the term "genome" means (all the genetic information contained in an organism or a cell).

        8. Have students view the Human Genome Project QuickTime Video to understand the fundamental importance of being able to map, or sequence, DNA. Then, have them go through the DNA Sequencing Flash Interactive to learn more about the techniques and tools scientists use to sequence the human genome.

        Lead a class discussion using the following to elicit student participation:

        • What data do scientists get when they sequence the human genome?
        • How has the way scientists read the genetic code changed in recent years?
        • Why is the map of the human genome only the first step in the Human Genome Project? What would be the next steps?

        9. Then, show students the DNA Databases QuickTime Video and Personal DNA Testing QuickTime Video. You can cue up the first video to the introduction of GeneChips®. [Note: This begins about two and a half minutes in. You may want to turn on the captions and look for where narrator Robert Krulwich says, "In fact, a lot of the technology already exists."] Watch the video through its completion. Show the second video from the beginning and stop before the introduction to George Church and the Personal Genome Project. [Note: This segment is about three minutes long. You may want to turn on the captions and stop where narrator Neil deGrasse Tyson says, "For now, skeptics say these tests may be no more predictive than a good family history."]

        10. Assign students the task of going to the Therapeutic Uses of Stem Cells Flash Interactive and learning about stem cell therapy. Then, have pairs of students select one of the diseases in the activity to learn how it might be treated with stem cells and what the goal of the stem cell therapy would be. Have them share their findings with another student pair.

        11. Extension Activity: Ask students to write a paragraph on how DNA sequencing, GeneChips®, and stem cell therapy could together be used to detect a genetic disorder and possibly correct it.

        Part IV: Privacy and Ethics (45-minute period)

        12. Genetic testing can reveal if a person has a genetic condition or may be predisposed to one. Biomedical researchers are working hard to find ways to cure such conditions. Gene therapy refers to methods that allow scientists to correct a genetic disorder by replacing a defective gene with a normal copy of the same gene.

        Genetic testing and gene therapy offer hope for many people, including those who either have or may be predisposed to a serious medical condition. But many others believe there is an opportunity for abuse in using the emerging tools of biotechnology, especially with the highly personal information that gets collected in testing.

        Show students the parts of DNA Databases and Personal DNA Testing you did not show them in Part III. These sections specifically deal with privacy and ethical issues. Show the first video from its beginning through when George Annas discusses who might benefit from having copies of someone's genetic profile. [Note: This segment lasts about two and a half minutes.] Cue up the second video to the introduction to George Church and the Personal Genome Project, and show it through its completion. [Note: This begins at about 3 minutes. You may want to turn on the captions and look for where the narrator says, "But what if we could find a cheap way to read not just SNPs, but the entire genomes of many people..."]

        13. Divide students in groups of four, and ask them to discuss and give written comments on the following:

        • List two or three of the ethical issues regarding the creation of DNA databases through DNA sequencing and PCR.
        • Name some ways in which each of the following groups stand to benefit or be harmed from the sharing of an individual's DNA as well as other personal/lifestyle information:
          • Drug companies
          • Medical practitioners
          • Insurers
          • Employers
          • The armed forces
          • The Department of Motor Vehicles
          • The "public"

        14. Extension Activity: Have students write a personal statement (that will only be seen by the instructor) that discusses whether they would agree to provide their DNA sample to the Human Genome Project or Personal Genome Project. Have them explain the reasons for their choice.

        Culminating Activity

        Have each student write a paragraph discussing his or her opinion on the value of spending more than 10 years and nearly $3 billion to sequence the entire DNA of humans. Why was this project so expensive and time consuming? Was this money well spent?

        For additional curriculum resources on biotechnology, check out Biotechnology: Science for the New Millennium by Ellyn Daugherty.

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