Albinism is a recessive trait. A man and woman both show normal pigmentation, but both have one parent who has albinism (without melanin pigmentation). What is the probability that their first child will have albinism?

Answer: 0,25

Step-by-step explanation:

As both the man and the woman have one parent who has albinism, they have the gene (though recessive). The genetic information is given 50% by each parent. The probability of the first child to have albinism is given by the probability of both parent to transfer the gene to him. It is:

P (W=yes ∩ M=yes);

where

P = probability

W = woman

∩ = intersection

M = man

Using the property of intersection in probability (when independient events), we have:

P (W=yes ∩ M=yes) = P (W=yes) * P (M=yes) = 0,5 * 0,5 = 0,25