1) Brown fur colour is dominant, gray colour is recessive.
2) Alleles for brown colour is Bb and alleles for gray colour is bb.
3) The parents are heterozygous dominant that is each one of them has one allele for recessive trait gray colour.
Explanation:
Alleles for fur colour brown is dominant
Alleles for fur colour gray is recessive.
Genotype for brown is BB, Bb
genotype for gray colour is bb
Two brown mated producing gray offspring must be heterozygous. the punnet square shows:
B b
B BB Bb
b Bb bb
75% of offspring are brown
25% of offspring are gray 3:1 phenotypic ratio, genotypic ratio 1:2:1
From the punnet square
The brown colour is dominant.
The gray colour is recessive.
Alleles gray colour is bb
alleles for brown is BB, Bb
The parents are heterozygous that is why when two recessive alleles combine of either parents in a progeny gray colour is expressed.
