Many contributing factors have been associated with the onset of cancer, including exposures
to carcinogens such as excessive exposure to UV radiation and to the chemicals found in
cigarettes. In addition, several forms of cancer have been found to have familial tendencies.
Current cancer research has uncovered many genes that are linked to various cancers and other
diseases and as is the case with most new technologies, how this information is obtained from
patients and handled will need to be approached cautiously in order to assure confidentiality of
the genetic profiles of individuals and their families. Although modern day advancements offer
several tests to identify the inheritance of a gene, genetic counselors still rely on traditional
methodologies such as the creation of a pedigree when determining an individual’s genetic
predisposition to specific types of cancers. In this activity students will construct a pedigree of
Henrietta’s family and then record and analyze the genetic history of the family over several
1. Construct a model that illustrates relationships within families, particularly large extended families.
2. Analyze the pattern of inheritance of a particular trait, disease or disorder.
3. Gather relevant medical information in order determine the mode of inheritance of genetic traits, disorders, and/or diseases within a family.
National Biotechnology Standards:
BT.2.1 Describe the major scientific discoveries that lead to development of recombinant DNA technology, including those in the fields of biology, chemistry, genetics, and microbiology, and explain how these advances in DNA technology are used today.
BT.2.3 Identify past and current discoveries and developments in fields such as, agriculture, diagnostics, medical devices, pharmaceuticals, and research and development.
Engage (Activate Student Thinking)
Introduce the purpose for the use of a pedigree. Provide students with a sample pedigree or utilize a pedigree displayed in the course textbook. Guide students through an analysis of the chart by explaining the symbols used thus when drawing or studying a family pedigree, the following are general guidelines to the symbols used and their representations:
• a circle represents a female
• a square represents a male
• a shaded circle or square refers to a person having some form of a trait, disease, or disorder (i.e. cancer)
• an open (non-shaded) square or circle represents a person who so NOT possess a particular trait, disease or disorder
• a circle or square (either shaded or open) with a diagonal slash through it represents a person who is deceased.
Explore (Guided/Student-Centered Activity)
1. Copy and distribute the student handout, The Henrietta Lacks Family Pedigree and instruct students to label the pedigree with the names of members of the maternal branch of Henrietta’s family as they read Chapter 2 – Clover (1920-1942) on pages 18-26 and Chapter 16 – Spending Eternity in the Same Place (1999) found within pages 122-126 of the text, The Immortal Life of Henrietta Lacks.
2. Instruct students to also record any diseases or disorders by shading in the circle or square and indicating the type of illness next to the individual’s symbol. They should also place a diagonal slash through the symbol of persons who are deceased according to the information provided in the reading excerpts listed in Step #1 above.
Explain (Formulate Ideas)
Students should repeat the activity by constructing, labeling, and analyzing a pedigree of the paternal branch of Henrietta’s family using the book excerpts indicated in Step #2 above. Ask students to identify and discuss any diseases or disorders that appear to “run” in this line of Henrietta’s family. Are the students able to make conclusions based on the information available? Why or why not?
Elaborate (Apply and Extend Understanding)
After placing students in small groups of 3-4 students, have students compare and contrast their completed pedigree with the other members of their group. Ask students to identify and discuss any diseases or disorders that appear to “run” in the Lacks Family. (Instructor’s Keys for both branches of Henrietta can be found on pages 16 and 17 of the BioEthics Exploration in High School Cellular Legacy Unit Guide).