Question

In some bees, thin stripes (S) are dominant over thick stripes (s) and black eyes (B) are dominant over gray eyes (b). Complete a dihybrid cross for parents with the genotypes: SsBB × ssBb. Describe how you would set up a Punnett square for this cross.

Answer 1

First find the gametes each parent is able to make:

Parent 1: Ss BB -> (Both s and S but only dominant B)

SB (gamete 1)
sB (gamete 2)

Parent 2: ssBb -> (Both B and b but only s)

sB (gamete 1)
sb (gamte 2)

cross both gametes