If both the mother and the father are carriers for the cystic fibrosis gene, what are the chances that their child will be a cystic fibrosis carrier?

Cystic fibrosis is a genetic disorder that is inherited in an autosomal recessive manner. This means that a person must inherit two copies of the defective gene (one from each parent) to have the disease. If both parents are carriers, they each have one copy of the defective gene and one normal gene.

Here's how the chances break down:

1. There's a 25% chance that the child will inherit two normal genes (one from each parent). In this case, the child will not have cystic fibrosis and will not be a carrier.

2. There's a 50% chance that the child will inherit one normal gene and one defective gene (making the child a carrier). This happens if the child inherits the normal gene from one parent and the defective gene from the other.

3. There's a 25% chance that the child will inherit two defective genes (one from each parent). In this case, the child will have cystic fibrosis.

So, if both parents are carriers, there's a 50% chance that their child will also be a carrier.