Cystic fibrosis is the most common lethal genetic disease among Caucasians. with cystic fibrosis produce a mutated chloride (Cl-) channel protein that results in abnormal ion and water transport across epithelia such as that lining the lung, often making it difficult to breathe. Cystic fibrosis is inherited in an autosomal recessive manner; individuals who are heterozygous for the cystic fibrosis allele are carriers but do not exhibit the disease. An individual who has the disease has children with an individual who does not have the disease and is not a carrier. What is the chance that their child will not have the disease

The correct answer would be - 100% chances that their child will not have the disease.

Explanation:

Cystic fibrosis is one of the lethal diseases that inherited in an autosomal recessive manner. The Autosomal recessive pattern takes place when the defected gene present in the autosome chromosomes of an individual and only exhibits when both copies of recessive gene present.

The affected person must have two copies of the recessive allele - cc and the gamete he will produce will be - c only, however in the normal person, both copy of allele must be dominant - CC and will produce the gamete - C only.

Then from Punnett square:

C C (normal parent)

(affected parent) c Cc Cc

c Cc Cc

By this, it is established that in case all the offspring will have one copy of dominant and one copy of recessive gene which means 100% chances of carrier child.

Thus, the correct answer would be - 100% chances that their child will not have the disease.