1. Human Genetic Pedigrees
Tracking your own family traits

2. What is a Genetic Pedigree?
A genetic pedigree is an easy way to track your family traits. It looks like a family tree, but also contains information about your genetic history.
For this activity you will indicate the inheritance patterns of the following traits, with a corresponding key.
Tongue Rolling – T or t – Tongue rolling is dominant
Hair Color – R or r – Black and Brown is dominant
Curly or Straight Hair – A or a – Curly is dominant
Eye Color – I or i – Black or brown is dominant
Thumb curve – L or l – Curve is recessive
Pinky curve – S or s – Bent is dominant

3. Assignment Tasks You will draw a pedigree in the following steps.
Draw all the family members for you, your siblings, your parents, and grandparents.
Make a Phenotype Key for all 6 traits.
Use symbols and annotations as indicated.

4. This shows three generations indicated by the roman numerals on the left .
Each individual in a generation is then numbered for each generation.
When possible, the older person is on the left, continuing in descending order.
Generations I II
III 1 2 3

5. Symbols Squares indicate males. Circles indicate females.
Solid line connecting male and female generally indicates marriage.
Vertical line indicates the couple has a child.
Dashed vertical lines are for adopted children.
Horizontal line for children continues to indicate all children for that couple.
Oldest child on the left, youngest on the right.
Symbols I 1 2 II 2 3 1
III 1

6. Remarriages Half or Step Siblings
Female 2 had two marriages.
They had a son.
Male 3 is the second husband.
They had a daughter.
Male 3 had a previous wife.
Here the siblings age is not necessarily in descending age order.
Remarriages Half or Step Siblings 1 2 3 4 I II
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7. Twins Identical twins split the sibling line at an angle.
Fraternal twins are usually indicated with an annotation below each twin.
The genetic inheritance is the same as though they were born at different times.
Twins I 1 2 II 3 4 1 2
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8. Pedigree Sample ? Key: White shading = cannot roll (r)
Blue shading = can roll (R )
? = unknown phenotype

9. Rubric Three generations correctly annotated.
You are indicated on your family tree.
All 6 Phenotypes shown for family members.
Phenotype key with corresponding alleles
Name, date, and period is on the back.
Rough Draft – 2 adult signatures
Final Draft - Must use a ruler, in ink ( or computer)
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