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

Answer:

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)

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)