Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are both of normal pigmentation, but both have one parent who is albino (without melanin pigmentation). What is the probability that their first female child will have albinism?
A) 0
B) 1/8
C) 1/2
D) 1/4
E) 1/3

Question

Quizplus · Accepted Answer

Since both parents are heterozygous carriers of the recessive allele for albinism, they each have a 1/2 chance of passing on the recessive allele to their offspring. The probability of both parents passing the recessive allele to their first female child would be (1/2) x (1/2) = 1/4. Therefore, the probability of their first female child having albinism is 1/4, or D.

Albinism Is an Autosomal (Not Sex-Linked) Recessive Trait