Imagine that you are a doctor in a maternity ward. During your last shift, 20 bables were born. 10 had blue eyes, and 10 had brown eyes. Remember

genotypes are the two alleles given for each trait, written with a letter. For this activity B = brown eyes b = blue eyes. Phenotypes are the physical

appearance of the tralt.

Given the phenotypes, what are the possible genotypes for these bables?

Cultures

INFO

Answer: The possible genotypes for brown-eyed babies are BB and Bb while the possible genotype for blue-eyed babies is bb.

Explanation: From the information given above, B = allele for brown-eyes, B is dominant while b = allele for blue-eyes, b is recessive. A dominant allele is one that expresses itself in the presence of a recessive allele, it masks the effect of a recessive allele while a recessive allele is one that cannot express itself in the presence of a dominant allele, its effect is masked by a dominant allele. A recessive allele can only express itself in a homozygous state while a dominant allele expresses itself both in a homozygous and heterozygous state.

Brown-eyed babies will therefore have two possible genotypes: BB and Bb while blue-eyed babies will have one possible genotype: bb.