Please read the following scenario to answer the following question.
The parents of a child with unusual disease symptoms take the child to a doctor for help. The doctor suspects that the condition might have a genetic basis. She recommends that the child be taken to a specialty clinic where physicians and staff members are trained to diagnose genetic diseases and counsel parents. Ultimately, the child is diagnosed with a rare recessively inherited disease. The parents are tested for the gene, and both are found to be heterozygous. The parents want to have another child but are afraid this child will also be affected.
-What would genetic counselors say is the probability that the second child will have the disease?
A)1/2
B)1/4
C)1/8
D)1/16

Question

Quizplus · Accepted Answer

The parents are both heterozygous, which means they each have one copy of the normal gene and one copy of the mutated gene. When they have a child, each parent has a 50% chance of passing on the normal gene and a 50% chance of passing on the mutated gene. If both parents pass on the mutated gene, the child will have the disease. If one parent passes on the normal gene and the other parent passes on the mutated gene, the child will be a carrier, but will not have the disease. If both parents pass on the normal gene, the child will not have the disease or be a carrier. Therefore, the probability that the second child will have the disease is 1/4.

Please Read the Following Scenario to Answer the Following Question