Mark Twain IS 239 School for the Gifted and Talented
Karen Ditolla, Principal
Name:__________________________________________________________Date:________________________
8________ID_________
Ms. Baraquia
3rd Quarter Project
Family Tree (Pedigree)
Due date:_____________________
Introduction:
A pedigree is a family tree that shows the relationships among family
members and traces a specific genetic trait within the family. It is a
“shorthand” way to represent the members of a family.
By following a few guidelines and using what you have learned in class about
heredity and dominant and recessive traits make a pedigree chart for your
family. You might even be able to find a pattern in the way a family
characteristic is inherited.
Directions:
1. Using a poster board, create your family pedigree of one particular trait.
(Traits are listed below.) Include the following:
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Use the designated pedigree symbols and a legend
first names for all members and add a photo of each member
A title detailing what trait you will explore
Indicate each member’s allele, homozygous and/or heterozygous.
Indicate whether the trait is dominant or recessive.
Create a Punnett square of 2 people (indicate their names) with
known genotypes. What are the possible offspring’s genotypes and
phenotypes?
Indicate the genotype of each person (If there are several
possible genotypes, put a question mark for that allele.) Example:
Tongue roller (T?)
Possible traits:
Trait
Eyelash length
Widow’s peak
Dimples
Freckles
Ear lobes
Hair on middle digit
Hand use
Tongue roller
Height
Curved Thumb
Dominant
long (1 cm or more)
widow’s peak
Dimples
Freckles
Free ear lobes
Hair on middle digit
Right-handed
Tongue roller
Short
Females: less than 5’7
Males: less than 5’10
Hitchhiker thumb
Recessive
short (less than 1 cm)
straight hairline
No dimples
No freckles
Attached
No hair on middle digit
Left-handed
Non-tongue roller
Tall
5’7 or above
5’10 or above
Straight Thumb
2. Remember to be creative! Your pedigree will identify:
a Males & females
b. How people are related
c. Who has the trait and who does not
3. Once your pedigree is complete, attach your paragraph. You should follow
these criteria for the paragraph.
 Type a strong and well-written paragraph (6+ sentences) explaining
your reasoning ( tell me how you know),
 Include examples from your pedigree to make your argument for
dominant or recessive.
EXAMPLE PARAGRAPH:
EXPLAINING IF TRAIT IS DOMINANT OR RECESSIVE
Crim Family Widow’s Peak Pedigree
I examined my family’s pedigree and researched the Widow’s peak trait and
have determined that the trait is a recessive one. To figure this out, I first
looked at my pedigree. You will see that John and Vickie both have the trait,
and so do all five of their children. I also noticed that Grandma & Grandpa
Zoelle both had it, and so did all eleven of their children. I was not certain
that it was recessive, because this pattern could be shown if the trait is
dominant and John, Vickie, and Grandma and Grandpa Zoelle were all
homozygous dominant. However, I looked up the trait in our textbook, and
according to the book the trait is recessive.
**This is an example only. Be sure to write your own paragraph! Do not copy
this sample!**