A man who has phenylketonuria (metabolic genetic disorder) marries a woman who is heterozygous at that locus. What is the probability that their first child will have phenylketonuria?

Plz help asap

Use Pennett square for father (pp) and mother (Np).

https://www.google.com/search?client=safari&rls=en&q=punnett+square&ie=UTF-8&oe=UTF-8&gws_rd=ssl

To determine the probability that their first child will have phenylketonuria (PKU), we need to consider the inheritance patterns of the disorder.

Phenylketonuria is an autosomal recessive disorder, which means that it requires two copies of the faulty gene to be inherited for the disorder to manifest. A person who is heterozygous for PKU carries one allele for the disorder (P) and one normal allele (p).

In this case, the man has phenylketonuria and is likely homozygous for the disorder (PP), while the woman is heterozygous (Pp). To determine the probability that their child will have PKU, we need to consider the possible combinations of alleles that the child can inherit from the parents.

There are four possible combinations of alleles that the child can inherit when considering the parents' genotypes:

1. PP (25% probability): The child inherits the faulty allele from both parents, resulting in the child having PKU.
2. Pp (50% probability): The child inherits one normal allele (from the heterozygous mother) and one faulty allele (from the father with PKU). In this case, the child will be a carrier of the disorder but will not have PKU.
3. pP (50% probability): The child inherits one faulty allele (from the father with PKU) and one normal allele (from the heterozygous mother). Similar to the previous case, the child will be a carrier but will not have PKU.
4. pp (25% probability): The child inherits two normal alleles, one from each parent. In this scenario, the child does not have PKU and is not a carrier of the disorder.

To find the probability that their first child will have PKU, we add up the probabilities of the first two scenarios: PP (25%) + Pp (50%) = 75%. Therefore, there is a 75% chance that their first child will have phenylketonuria.