Question

Albinism is known to be due to an autosomal recessive mutation. The first child of a couple with normal skin pigmentation was an albino. What is the probability that their second child will also be an albino ?

(a) 100%

(b) 25%

(c) 50%

(d) 75%

Answer 1

Correct option (b) 25%

Explanation

Since, albinism is a recessive character, a child will be albino only if it is homozygous for albinism genes. Since, parents have normal skin, it means they are heterozygous. As a result of cross between two heterozygous parents, 25% of the children will be homozygous recessive. The nature oft he second child is not affected in any way by the nature of the first child because both are independent events.