Question

Imagine that a given species has a gene for hair color (B = dominant brown, b = recessive white) and a gene that controls hair length (S = dominant short, s = recessive long). Complete the dihybrid cross between parents with the genotypes: BBSS and BbSs. Then list the genotypes and phenotypes of the possible offspring that can be produced.

Answer 1

Phenotypes: All Brown Hair Color and All Short Hair Length

Genotypes:

Homozygous dominant hair color and homozygous dominant hair length: (BBSS, BBSS, BBSS, BBSS).

Homozygous dominant hair color and heterozygous hair length: (BBSs, BBSs, BBSs, BBSs)

Heterozygous hair color and homozygous dominant hair length: (BbSS, BbSS, BbSS, BbSS)

Heterozygous hair colour and heterozygous hair length: (BbSs, BbSs, BbSs, BbSs)

Step-by-step explanation:

Hair color :

B = dominant brown

b = recessive white

Hair length :

S = dominant short

s = recessive long

The dihybrid cross between parents with the genotypes:

BBSS × BbSs

If BBSS self crossed; we have the following traits= BS, BS, BS, BS

If BbSs self crossed; we have the following traits= BS, Bs, bS, bs

The dihybrid cross is as follows:

BS BS BS BS

BS BBSS BBSS BBSS BBSS

Bs BBSs BBSs BBSs BBSs

bS BbSS BbSS BbSS BbSS

bs BbSs BbSs BbSs BbSs

Phenotypes = All Brown Hair Color and All Short Hair Length

Genotypes include:

Homozygous dominant hair color and homozygous dominant hair length: (BBSS, BBSS, BBSS, BBSS).

Homozygous dominant hair color and heterozygous hair length: (BBSs, BBSs, BBSs, BBSs)

Heterozygous hair color and homozygous dominant hair length: (BbSS, BbSS, BbSS, BbSS)

Heterozygous hair colour and heterozygous hair length: (BbSs, BbSs, BbSs, BbSs)