The Pedigree
No silly….not the dog food!
The Pedigree
Sometimes the Punnett square doesn’t cut it
Pedigrees allow us to see generations
They allow us to follow certain traits
throughout a family history
Symbols
Males are represented by:
Females are represented by:
Shading marks the traits
Lines
Lines can tell us:
The relationship among individuals
Who is dead
Who are twins
Are these twins identical? How can you tell?
Take a look See
Some Vocab.
Autosomal trait
Trait that appears equally in both males and
females (do you remember what Automsomes
are???)
Sex Linked trait
A trait that is located on the X chromosome,
because males only have one X c’come they if
they have a sex linked trait they will exhibit that
phenotype for the tait.
Sex linked traits
Hemophilia
Color blindness
Females that are heterozygous for a sex
linked trait will be “carriers.” Females can
only show the trait if they are homozygous for
that trait.
So how could a woman be color blind or have
hemophilia????
Showing Sex linked
Genotypes/Phenotypes
XX normal female
XcX Female carrier for Colorblindness
XcXc Colorblind Female
Showing Sex linked
Genotypes/Phenotypes
XY Normal male
XhY male with hemophilia