1. Show the videos Alzheimer's Disease and A Family Disease. Ask students to discuss the following in small groups:

• Would you choose to be tested if you knew genetically related breast cancer or Alzheimer's disease ran in your family? Why or why not?

2. Have students use the Personal Opinion Record (PDF) sheet to record their decision and explanation for it under the heading "Take One."

3. Survey the class for the results of their discussion, and record it on the board.

4. Introduce the video Preimplantation Genetic Diagnosis as one of the newest ways to do prenatal testing. Discuss the following:

• At what stage of embryo development does Preimplantation Genetic Diagnosis (PGD) take place? Why is it done at this stage?
• Why would PGD be especially valuable for preventing sex-linked diseases?
• What are the benefits and risks of PGD?

5. Hand out and have all students read the section "What is gene testing?" from Understanding Gene Testing noting questions that arise during their reading. Answer any student questions.

6. Give students the four jigsaw sections from Understanding Gene Testing and have them explore genetic testing by doing a jigsaw (Jigsaw Explanation (PDF)). Have teams of students divide up and read their assigned sections from Understanding Gene Testing identifying at least three key ideas. Then have students teach the key ideas of their topic to the rest of their group.

7. When teams have completed the jigsaw, ask students if what they have just learned causes them to reconsider their earlier decision about genetic testing, which they recorded on their Personal Opinion Record (PDF) sheet. Have them write their current decision under the heading "Take Two."

8. Show the video Finding Disease Genes. Ask:

• How can pedigrees (family trees) help identify inherited diseases?
• What are the benefits of combining information about a person's DNA, medical history and family tree into a database? What concerns might people have about this?

9. Give out and have students read the section "How do scientists develop predictive gene tests?" from Understanding Gene Testing. This section describes how researchers create pedigrees for genetic diseases.

10. Ask students if what they have just learned makes them reconsider their earlier decision about genetic testing, which they recorded on their Personal Opinion Record (PDF) sheet. Have them write their current decision under the heading "Take Three."

11. Have students read the Nature vs. Nurture Revisited essay.

12. Ask students if what they have just learned causes them to reconsider their decision about genetic testing once again. Have them write their current position and explanation under the heading "Take Four."

13. Have students read How to Conquer a Genetic Disease. Then show the Genetic Therapy and Breast Tumors and Finding Cures Is Hard videos to demonstrate to students how medical researchers are beginning to use what they have learned to treat genetic diseases.

14. Ask students one last time if what they have just learned causes them to reconsider their earlier decisions about genetic testing. Restate the question:

• Would you choose to be tested if you knew breast cancer, Alzheimer's disease, or another genetic disease ran in your family? Why or why not?

Have them write their final decision under the heading "Final Take." Tally class results again and compare them to the first results on the board. Discuss any changes in opinions. Ask:

• If you changed your opinion, what caused you to change it?

15. Optional: Have students write an essay explaining their decision about genetic testing.