1. Example: Let’s examine a dog’s hair color AND a dog’s eye color
Dihybrid Cross
A cross between individuals which examines and predicts TWO trait combinations at one time
Example: Let’s examine a dog’s hair color AND a dog’s eye color
Brown hair (B) is dominant to white hair (bb)
Green eyes (G) are dominant to blue eyes (gg)

2. Mommy Dog
Let’s say our mom dog is heterozygous for her brown fur and heterozygous for green eyes.
What is her genotype?
BbGg
She can produce eggs with what combinations? Remember, the B alleles and G alleles will get split during meiosis!

3. BbGg
FOIL! BG Bg bG bg

4. Daddy dog
What if the dad is homozygous for brown hair and has blue eyes?
Genotype?
Allele combinations?

5. BBgg
FOIL! Bg Bg Bg Bg

6. Now let’s set up our cross!BG Bg bG bg Bg Bg Bg Bg

7. What about this cross? BbGg x BbGg

8. Now try one on your own…
Mommy dog has white fur and is heterozygous for green eyes.
Daddy dog is heterozygous for his brown fur and has blue eyes.
How many dogs would you expect to have brown hair and green eyes?
Brown hair and blue eyes?
White hair and green eyes?
White hair and blue eyes?