If your mother has cystic fibrosis, which is caused by a recessive allele, the odds of you having cystic fibrosis are ____.
A) 1/4
B) 1/2
C) 3/4
D) 1
E) impossible to determine without knowing your father's genotype

Question

Quizplus · Accepted Answer

Cystic fibrosis is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the faulty gene, one from each parent, to have the disease. The probability of inheriting the disease from a mother with cystic fibrosis also depends on the father's genotype. If the father is a carrier or has cystic fibrosis, the probabilities change, making it impossible to determine the odds without knowing the father's genotype.

If Your Mother Has Cystic Fibrosis, Which Is Caused by a Recessive