Transcript Pedigrees!

Pedigree Notes
June 2, 2016
What is a pedigree?
 A pedigree is a diagram of family relationships that
uses symbols to represent people and lines to
represent genetic relationships
 Make it easier to visualize relationships within
families
 Particularly large extended families (i.e. Royal
families)
 Often used to determine the mode of inheritance
(dominant, recessive, etc.) of genetic diseases
Sample Pedigree
Circles
represent
Females
P
F1
Vertical lines
extending
downward from F2
a
couple represent
their children
Squares
represent
Males
Horizontal lines connecting a
male and female represent
mating
Subsequent generations are written underneath
the parent generations, so oldest individuals are
at the top
What is the purpose of pedigree?
 Most times pedigrees are used to analyze the
pattern of inheritance of a particular trait
You shade in the symbol of all individuals
that possess the trait you are trying to
analyze
Some other pedigree symbols
 You already know:
1. Unfilled and filled
square
2. Unfilled and filled
square
3. Horizontal lines =
mating
4. Vertical lines = kids
 Other symbols you may see:
1. Square/circle with slash
through it = deceased
2. Triangle shaped lines from
parents to indicate twins
Let’s Do Some Practice!
 Turn your paper over to the back
 Work with the person sitting next to you to
try and figure out the possible genotypes for
the family members in the pedigree