Question

PART 2: Test Crosses (Medium difficulty problem)

3. Callie has brown eyes, but her husband Joseph has blue eyes. All three of their children have
brown eyes. Do you know what Callie's genotype is? If yes, what is it? If no, why not?

Help please!!

Answer 1

Since Callie has brown eyes, and all her children have brown eyes, we can only assume that the phenotype of brown eyes is dominand and Callie will have a dominant genotype, leaving Joseph to have a reccesive genotype (if Joseph was heterozygous for this aspect, he would have brown eyes) and the children will be heterozygous, with brown eyes as this characteristic predominates over blue eyes.