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Name _______________________________________________________
Date ___________
Activity: Investigating a Human Pedigree
Goal: To trace the gene that causes a genetic disorder through a
fictional family.
Problem: As a scientist, you’ve noticed that a genetic condition, “Whirling
Disorder,” runs in families, and you want to find the gene responsible for it.
(Individuals afflicted with this disorder let loose and dance uncontrollably when
they hear Rolling Stones tunes, even if remade as Musak!)
Your first step is to identify a large family in which some individuals have the
disorder, and others don’t. After enlisting the family’s support and collecting DNA
samples from all family members, you’re ready to begin looking for the gene.
Next, you draw up a pedigree, which is a diagram that shows how family
members are related and which individuals have “Whirling Disorder.”
Background Information: Here’s one way to think about genes. Say the genetic
information in each family member is like a jigsaw puzzle. Each puzzle piece
would represent a set of genes organized in a specific way, similar to a
chromosome. (Instead of 23 sets of chromosomes in every cell – each with
thousands of genes, think of jigsaw puzzles of genes in every cell.) Because all
humans have the same set of genes, arranged in the same order, every family
member would have the same basic set of puzzle pieces. A genetic human
jigsaw puzzle might look like this:
But the information carried in genes
differs slightly from person to person.
This is what makes each of us unique.
As a result, the colors of the puzzle
pieces would be different between
family members. While some relatives
might share puzzle pieces of a certain
color, other pieces would be different.
Only identical twins share the exact
same combination of colors.
Materials: “Whirling Disorder” family pedigree chart, genetic jigsaw puzzle sheet
with 12 members of the family represented and a blank “worksheet” puzzle.
Procedure:
1. What I Know: Write two sentences about what you already know about
pedigree charts and human inheritance.
2. Study the family pedigree chart and then study each puzzle. Each puzzle
has a number that corresponds to an individual in the pedigree.
3. Find the puzzle piece that is responsible for “Whirling Disorder.
4. What I Observed: Write the number of the puzzle piece that is
responsible for “Whirling Disorder.”
Number of Piece _________
5. Questions: Answer the following questions in complete sentences.
a. How did you determine which puzzle piece is responsible for
“Whirling Disorder?”
b. How do you know the puzzle piece you chose is the right one?
c. In this simulation activity what unit of heredity does each puzzle
piece represent?
d. Is “Whirling Disorder” sex-linked? Explain your answer.
e. Is “Whirling Disorder” dominant or recessive? Explain your choice.
6. What I Wonder: Pose a question that you may still have concerning the
topic of this activity.
7. Claim and Evidence Writing Prompts: Use the following prompts to help
you construct your lab conclusion, What I Learned.
 Goal: State the goal of this lesson.
The goal of this lesson is…
 Claim: What did you learn from the activity that satisfies the goal of
this lesson? This is an I Learned statement.
I learned that…
 Evidence: How can you prove from your observations that you
learned what you claim? This can be a general statement that you
will explain in detail in your explanation.
I know this because….
 Explanation: Use specific data from your observations to support
your claim and describe the evidence. Use details to support
your claim.
 Concluding Statement: Reword the goal and either add
information you learned about the topic from your text book, class
discussions, and/ or personal research OR you can extend the
statement by adding a relevant question.
8. What I Learned: Write at least a one paragraph summary of what you
learned from completing this activity. Use the Claims and Evidence Writing
Prompts to help you compose your summary.
9. What I Wonder: Pose a question that you may still have concerning the
topic of this activity.
10. Questions: Answer the following questions in complete sentences.
a. How did you determine which puzzle piece is responsible for
“Whirling Disorder?”
b. How do you know the puzzle piece you chose is the right one?
c. In this simulation activity what unit of heredity does each puzzle
piece represent?
d. Is “Whirling Disorder” sex-linked? Explain your answer.
e. Is “Whirling Disorder” dominant or recessive? Explain your choice.