In humans, dimples are a trait that exhibits simple dominance. The two alleles for this trait are dimples (D) and no dimples (d). A dimpled man whose mother has no dimples marries a woman with no dimples. What is the probability that their first child will have dimples?

Question

Biology

Dummy

28 December, 19:00

In humans, dimples are a trait that exhibits simple dominance. The two alleles for this trait are dimples (D) and no dimples (d). A dimpled man whose mother has no dimples marries a woman with no dimples. What is the probability that their first child will have dimples?

+1

Answers (1)

Know the Answer?

Joyce Baxter · Answer 1

The probability is ½

Explanation:

Since the dimple trait is simple dominance, it therefore can be inherited in both the homozygous (DD) and heterozygous form (Dd). For non dimples we have (dd).

Thus, for a dimpled man whose mother has no dimples, it can be concluded that he is an heterozygote. (For him to be dimpled with a non dimpled mom, his dad has to be either an homozygous/heterozygous dimpled man. Since his mom is non dimpled (dd), therefore he can only be an heterozygous)

Therefore, a cross between a dimpled man (Dd) and a non dimpled woman will give.

Dd x dd

Dd dd

½ ½

50% 50%