In humans, "unattached earlobes are dominant over "attached earlobes. A woman and a man, both with unattached earlobes, have a child with attached earlobes. What is the probability their next child will have attached earlobes?

Question

Quizplus · Accepted Answer

Since both parents have unattached earlobes but produced a child with attached earlobes, they must both be heterozygous (Aa) for the trait. The Punnett square for two heterozygous parents is Aa x Aa, which results in a 1/4 chance of an aa offspring (attached earlobes).

In Humans, "Unattached Earlobes Are Dominant Over "Attached Earlobes