Pedigree
• What do you think of when you read the
above word?
– Dog food
– Family
– Lineage
– inheritance
Pedigree
• Chart that shows how a trait and the
genes that control it are inherited in a
family.
Pedigree
-Females are circles
-Males are squares
-Shading is an individual with the trait
-Individual carrying the trait
Pedigree
• Marriage / mating
• Offspring
(in order of birth)
1
2
3
4
• Sex unknown
Finding a Gene on the Chromosome Map
»We can examine inheritance in a family by constructing a pedigree.
»In this family certain members (in black) have Whirling disorder.
Finding a Gene on the Chromosome Map
How do scientists find the genes responsible for a hereditary
disease in a family?
»Think of all the genes in a person’s genome as
puzzle pieces in a jigsaw puzzle.
»Each piece represents a different gene.
»Because all humans have the same set of genes
in the same order, every family member has the
same basic jigsaw puzzle arrangement.
Finding a Gene on the Chromosome Map
How do scientists find the genes responsible for a hereditary
disease in a family?
»Genes are passed from parent to child.
»Different colors represent different alleles (forms) of a gene.
Finding a Gene on the Chromosome Map
Examine the following pedigree and the
corresponding jigsaw puzzle genomes of the family
members.
(Scientists would be examining the pattern of bands
left by each person’s DNA in a gel.)
Use the process of elimination to find the gene for
Whirling disorder.
(First person to identify the gene using the
numbered guide, yell GENE!)
1
2
3
4
5
6
7
8
9
10
11
12
Make a pedigree based on the
following passage about freckles.
1. Although Jane and Joe Smith have
dimples, their daughter, Clarissa, does
not. Joe’s dad has dimples, but his
mother and his sister, Grace, do not.
Jane’s dad, Mr. Renaldo, her brother,
Jorge, and her sister, Emily, do not
have dimples, but her mother does.
Mrs Renaldo
Emily
Mr. Renaldo
Jorge
Jane
Mrs. Smith
Joe
Clarisa
Mr. Smith
Grace
• Andy, Penny, and Delbert have freckles,
but their mother, Mrs. Cummins, does
not. Mrs. Biodano, Mrs. Cummins’s
sister, has freckles, but her parents, Mr.
And Mrs. Lutz, do not. Deidra and
Darlene Giordano are freckled, but their
sister, Dixie, like her father, is not
freckled.
Your Pedigree
• Make a Pedigree based on your family.
Include the following:
– 3 generations
– One trait (hair, dimples, eye color, etc)
– Names
– Key
Mr. Penner’s Pedigree