The alleles are numbered 1 through 12. http://www.pbs.org/wgbh/nova/sciencenow/0406/01.html. Ask students to discuss whether or not they would want to know their own genetic risks for particular diseases or if they would allow their genetic information to be used for research. Students use Web resources effectively to determine the genetic risks of disease and to answer questions. Lung Disease: Alpha-1 Antitrypsin Deficiency, Medline Plus Alpha-1 Antitrypsin Deficiency, https://genographic.nationalgeographic.com/genographic/participate.html, * genotypes potentially affected by breast cancer, Completing genetic analysis and answering questions on the, A six-sided die for each pair of students. Ask students to bring in dice from home; obtain extras for those who forget. Character Analysis Some diseases are simply caused by a defect in one gene. If necessary, review relevant terms and concepts, including: Give each student a copy of the handouts and have students form pairs. In this activity you will examine the locations throughout the genome of genes that when mutated cause cancer to develop (i.e., cancer genes) and you will learn about the normal functions of these genes. Other genetically caused diseases are more complicated. Presumably, the wealth of data from the Human Genome Project and other research will permit more definitive answers in the future. Disadvantages include: genetic testing cannot predict the future; it can be expensive; and it could be used to discriminate against people. As a class, watch the NOVA scienceNOW segment Personal Genomes. The relationship between chromosomes and genes. Discuss students' results and answers to the questions on the "Checking Up on Genes" student handout. Demonstrate a sample Punnett square on the board, such as the following, which shows a heterozygous parent (Bb) mating with a homozygous recessive (bb) parent: Did the recommendations differ among the patients? recessive, and dominant, Apply the above terms to diseases with different inheritance patterns, Differentiate between genetic risk and lifestyle risk, in the context of disease, Demonstrate the use of Punnett squares to predict the probabilities of particular The genes of any species, including Homo sapiens, constitute one record of its evolutionary history.
PROCEDURE . In another example, two genes—BRCA1 and BRCA2—are strongly linked to breast and ovarian cancer. Different diseases are inherited in different ways. Can doctors predict who will get a particular disease based on a genotype for one gene alone? Form an opinion and support your response with facts and examples. For example, a type of lung disease known as Alpha-1 Antitrypsin Deficiency is caused by a defective SERPINA1 gene. Why or why not?
The “Activity 1 and 2 Documents” include student … Students can apply patient information to make recommendations. These genetic data do not demonstrate that one or the other hypothesis is correct, but rather they provide insights into the origin and movement of modern human beings. Some people choose genetic testing for other reasons, such as for help in deciding whether to have children or to contribute to research focused on learning about a disease and developing cures. Answers will vary, but be sure that students have used and interpreted Punnett squares correctly.
What is the difference between a Punnett square and a pedigree? The breast cancer 1 (BRCA1) gene has been implicated in breast cancer. When students are finished, lead a discussion. The influence of factors other than genes depends on each individual's genotype. But because many diseases are influenced by many genes and the relationships between all genes are unknown, the answer is usually no.
Which hypothesis do the data support more strongly? (See answer below.).
Use the following rubric to assess each team's work. Answers will vary, but check that students have correctly identified the appropriate actions for each disease and interpreted the role of lifestyle choices for each disease genotype: Punnett Squares and the Future Generation
0 Have students consider personal and public genome sequencing. Bookmark the following Web pages on class computers: Allele — one of the variant forms of a gene, Gene — a functional portion of DNA that is passed from parent to offspring and which usually codes for a specific protein, Dominant allele — an allele that almost always results in a specific trait, even if the person possesses only one copy, Recessive allele — an allele that only results in a specific trait if the person possesses two copies of the recessive allele, Genotype — the genetic identity of an individual, Heterozygous — having two different forms of a particular gene, Homozygous — having two of the same forms of a particular gene, Punnett square — a tool used to predict the genetic outcome of a mating, Pedigrees — a pictorial representation of a family's health history. 0638931. genotypes in a future generation, Discuss how disease can be affected by lifestyle, Debate the pros and cons of genetic testing. Then students will analyze genetic data for their "patients," compare their characters' risks of developing the diseases, and predict the disease risks for the next generation. Students need assistance determining how specific genotypes relate to disease and are able to answer questions adequately. %%EOF endstream endobj 318 0 obj <>/Metadata 80 0 R/Outlines 146 0 R/PageLayout/OneColumn/Pages 315 0 R/StructTreeRoot 162 0 R/Type/Catalog>> endobj 319 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageC/ImageI]/XObject<>>>/Rotate 0/StructParents 0/Type/Page>> endobj 320 0 obj <>stream Grades 9-12 Ask students to determine the proportion of the children with each genotype. No. h��Y�n�H���>&X�;��\�'��⍓qf�~`$�""��D'�|��SM*�,'v����f�/�u9�U��%ib]�h���6|��2�g���&6�7çN�e&ɴ��&Y����1�[�|��s6��p�'.R�Q$֧�)�����c��4l�SL�����%� g�'��Ip������#���~Ɖ�|����:x�Of�f\�.�<>8. Recall the two major hypotheses about the origin of modern human beings: Consider the two sets of data you have examined.
Translation and Transcription Activity Make 1 copy per student (or alternatively, one per group of 3–5 students) of the blank Genetic Mutations Worksheet and the Codon Chart handout for the genetic mutations activity. In this activity, students play the role of doctors interpreting patients' genetic test results. However, testing for early-onset Alzheimer's disease could result in a person feeling despair over a condition for which there is currently no treatment or cure. Learning Objectives For every gene, we inherit one copy, known as an allele, from each parent. Note that the maps show the number of alleles and (unique alleles) per continental population. Students will play the role of genetic counselors who counsel patients about their genetic test results for genes associated with the three diseases. For some diseases, such as lung disease, knowing the genotype can be very useful because specific treatments are available (such as enzyme infusions) that would not be used if the diagnosis were a different type of lung disease. Scientists still disagree about whether the African replacement model (also called the "Out of Africa" model" or the multiregional evolution model is correct. Did the Punnett square help predict what genotype the child got? The answer depends on the disease, how it is inherited, and whether or not it is influenced by other factors. Student Handout 1 DNA Bioinformatics Study to Locate Human BRCA Cancer Genes Bioinformatics is the study of genetics and molecular biology by retrieval and analysis of biochemical and biological data using mathematics and computer science.
What accounts for this variation? For example, genetic testing for alpha-1 antitrypsin deficiency, or for breast cancer, could give a person important insights into his or her health, leading to more diligent screening and better prevention and treatment. In terms of subsequent generations, do children inherit the same disease risks their parents have?
Activity 2: Using Genes to Trace Human History. 317 0 obj <> endobj Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Hint: If hypothesis 1 is correct, what would you predict about the amount of global genetic variation by region? endstream endobj startxref