Dihybrid Cross Question

Question

Calculate the probable phenotypes of children born to a blue-eyed woman who is a carrier for color-blindness and a heterozygous brown-eyed man who is color-blind.

Answer 1

Let B = brown eyes and b = blue eyes

XC = normal color vision, Xc = color blind allele

Mom is bbXCXc and Dad is BbXcY

Mom's gametes are bXC and bXc Dad's gametes are BXc, BY, bXc and bY

Punnett Square (without lines):

bXC bXc

BXc BbXCXc BbXcXc

Brown color bld fem Brown color blnd fem

BY BbXCY BbXcY

Brown norm male

bXc

bY