A man and woman undergo genetic testing before conceiving a child. They discover that only the male is a carrier for Tay-Sachs disease. What are the chances that their offspring will be a carrier for Tay-Sachs disease as well?
A)100%
B)75%
C)50%
D)25%
E)0%

Question

Quizplus · Accepted Answer

If only the male is a carrier for Tay-Sachs disease, then he has one normal gene and one Tay-Sachs disease gene. The female likely has two normal genes. When they have a child, each parent will randomly pass down one gene to the child. There is a 50% chance that the child will receive the Tay-Sachs disease gene from the father and a 50% chance that the child will receive the normal gene from the father. If the child receives the normal gene from the father, the child cannot be a carrier for Tay-Sachs disease. If the child receives the Tay-Sachs disease gene from the father, then the child will be a carrier for Tay-Sachs disease like the father.

A Man and Woman Undergo Genetic Testing Before Conceiving a Child