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Cracking the Code of Life

Viewing Ideas

Before Watching

1. To help students understand terminology, review the concepts of and relationships among DNA, genes, protein, chromosomes, and traits. Stress that traits are the result of gene expression. Not all traits are visible to the eye (blood type, for instance) but some that students can see easily are hair color, eye color, and shape of face.

2. Help students make a connection between the word mutation and the physical change in a chemical base in the DNA molecule. Ask them to identify how the amino acid sequence would be changed if the triplet in the sequence, ACT, were changed to CAT.

After Watching

1. Sequencing the human genome may bring to light a number of genes that are the basis for known genetic diseases or that predispose a person to a condition such as heart disease, cancer, or Alzheimer's disease. Yet finding a gene for an illness may not lead to an immediate cure. Would students want to be tested to learn whether they had a genetic disease or predisposition if no cure was available? Why or why not?

2. Have students consider a scenario in which a lab needs DNA samples for use in genetic testing studies. Researchers are searching for a variant of a gene that provides resistance to specific bacterial diseases. If the company finds this gene, it may be able to produce a drug to sell to people who have these diseases. Would students agree to have their DNA be part of the study? Why or why not? Would they want royalties for their part in finding the gene? What if during the testing the company discovered they had a gene that might result in a health problem later in life? Would they want to be informed? Why or why not?

3. As more is learned about genes, there is a risk that the information will be used to define certain members of society by their genetic makeup. Ask students to identify the meaning of the terms genetic discrimination and genetic privacy. What are some ways to protect against this type of genetic discrimination?

When Talking About Genetics
Some students may know of someone with a genetic disease. Try to be sensitive to students' feelings by using language that addresses the idea of genetic mutations, or variations, rather than pejorative terms like defective, or inadequate, genes. Let students know that everyone has mutations in their genetic makeup; not all of these are harmful. Some genetic variations are neutral and others are beneficial.