Question

A scientist asks you for help studying fruit fly genetics. She asks you to determine the possible phenotypic ratio for two traits. She gives you the following information and asks you to do the dihybrid cross. Fill in the Punnett Square by completing items 1-5. Then write down the phenotypic ratio.
Body color: Ebony (E) or yellow (e)
Eye color: Red (R) or orange (r)

Answer 1

When you combine the genotypes in the Punnet square you get :
1. EeRR
2.Eerr
3.EeRr
4.eerr
The ratio would be typical for a dihybrid cross: 9 of the individuals with both dominant traits, 3 of the individuals dominant for one trait, 3 dominant for the other trait and only one recessive for both traits.
There will be 9/16 of ebony flyes with red eyes
3-16 of ebony flies with orange eyes
3/16 of yellow flies with red eyes
1/16 of yellow flies with orange eyes