Question

2. Imagine that you are a doctor in a maternity ward. During your last shift, 20 babies 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 trait. Which color of eyes is dominant? How do you know this? What does this mean in terms of inheritance?

Answer 1

Usually a dominant gene is written with a Capitalized letter, and recessive with a Lower-cased letter. So I’m leaning toward Brown as dominant since it’s a 50/50 split in the #s of blue and brown eyes babies. This means whenever one of the allele’s combination includes B, the eye color of the baby will be brown. The only way for a baby to have blue eyes is if the baby carries bb.