Question

Brown hair is dominant over red hair. What will the genotypes and phenotypes of the offspring of a cross between a homozygous brown hair person and a heterozygous brown hair person?

Do the process in five steps.

1.

2.

3.

4.

5.

Answer 1

1) Lets consider the allele for the dominant brown trait to be B and the allele for the recessive trait to be b.

2) The genotype for the homozygous trait will be BB, the genotype for the heterozygous trait will be Bb.

3) The punnet square shall be drawn as follows:

B b

B BB Bb

B BB Bb

4) The phenotype of the children from homozygous brown and heterozygous brown parents will be all brown hair coloured children.

5) The genotype will be 2:2. Half of the offsprings will have the probability of carrying the heterozygous alleles for the trait (Bb) and half of the children will have the probability of carrying homozygous alleles for brown colour (BB).