Cystic fibrosis is a homozygous recessive condition. A geneticcounselor should advise concerned parents that , if each of themhas a parent who has cystic fibrosis yet neither of the concernedparents is affected, the probability of their potential childhaving cystic fibrosis is? the answer is 25%, but I do not know why the answer wouldn’tbe 0%. Because if its homozygous recessive then thatmeans the allele on both parents wouldn’t produce a child withcystic fibrosis . . .