Question

Cystic fibrosis is a recessive genetic disorder. Ron is homozygous dominant in ANSI is a carrier of cystic fibrosis use a punnets square to predict the probability that one of their children will have cystic fibrosis

Answer 1

From the details, Ron is a homozygous dominant for CF (FF) and his partner is a recessive carrier of CF mutation (Ff).

The probability will be the following:

Genotype: 50% of children with FF genotype (no mutation), 50% of children with Ff phenotype (carriers).

However, 0% of children will suffer from the classical form of the cystic fibrosis, as all of them will be at least one normal copy of CF gene. In addition, the classical form of the disease will manifest only in case of both mutated copies (ff).

Therefore, 0% of children will have cystic fibrosis.