AP BIOLOGY

Detailed explanation-1: -Of these three genotypes, only bb, the homozygous recessive genotype, will produce a phenotype of blue eyes. The heterozygous genotype and the homozygous dominant genotype both will produce brown eyes, though only the heterozygous genotype can pass on the gene for blue eyes.

Detailed explanation-2: -In humans, brown eyes (B) is dominant over blue eyes (b). A brown-eyed woman whose father had blue eyes married a man with blue eyes.

Detailed explanation-3: -For example, when someone has brown eyes, it doesn’t necessarily mean they have homozygous genes. It’s possible for them to have a combination, or “Bb”, having one dominant brown allele and one recessive blue allele. In this case, because brown is dominant over blue, they will have brown eyes.

Detailed explanation-4: -The allele for brown eyes is the most dominant allele and is always dominant over the other two alleles and the allele for green eyes is always dominant over the allele for blue eyes, which is always recessive.