1. How to figure out your genotype from your family tree
How to figure out your genotype from your family tree... Do a pedigree chart
You need to create a family tree and label each box as to who it is. See diagram below.
Females =
Males =
Grandmom
Grandpop
Mom
Dad
Sister/you
Brother
Sister
Brother/you

2. Next, put in the alleles that are known.
If the person shows the dominant trait, then put the
dominant allele in the first spot.
If the person shows the recessive trait, then put the
recessive allele in both slots.
Grandmom
Grandpop
Mom
Dad
Sister/you
Brother
Sister
Brother/you
_ _

3. Let's use eye color. B=brown b=blue
Known phenotypes:
Mom = brown Grandmom (mom)= blue Grandpop (mom)= brown
Dad = blue Grandmom (dad) = brown Grandpop (dad) = blue
Me = Brown Sister = blue
Put the letters where they belong
Grandmom
Grandpop
Mom
Dad
Sister/you
Brother
Sister
Brother/you
_ _ B b

4. Let's use eye color. B=brown b=blue
Known phenotypes:
Mom = brown Grandmom (mom)= blue Grandpop (mom)= brown
Dad = blue Grandmom (dad) = brown Grandpop (dad) = blue
Me = Brown Sister = blue
Put the letters where they belong
Grandmom
Grandpop
Mom
Dad
Sister/you
Brother
Sister
Brother/you
_ _ B b
This is what you know without using relationships to others.
Now fill in the letters due to relationships.

5. Mom = brown Grandmom (mom)= blue Grandpop (mom)= brown
Known phenotypes:
Mom = brown Grandmom (mom)= blue Grandpop (mom)= brown
Dad = blue Grandmom (dad) = brown Grandpop (dad) = blue
Me = Brown Sister = blue
Relationships:
Grandpop (Mom) has brown eyes but no way to tell what the second allele may be.
Grandmom (dad) has brown eyes but a blue eyed child. Second allele must be blue.
Mom has brown eyes with a blue eyed parent as well as a blue eyed child. Second allele
must be blue.
I have brown eyes with a blue eyed parent. Second allele must be blue. B B b ?
Grandmom
Grandpop
Mom
Dad
Sister/you
Brother
Sister
Brother/you
_ _ B b ? b b b