Answer:
<h2>2. Peter's maternal grandfather has PKU.</h2>
Explanation:
- Such type of the genetic disorder in which two copies of a gene must be mutated at a time is called autosomal recessive disorder such as sickle cell anemia, phenylketonuria, and some other diseases.
- When a sing copy of a gene is mutated in a person then this disorder is not appeared and the person is called a carrier.
- So when a child is born by two carrier parents then there is a chance that a child will be affected if both the parents donate mutated genes.
- In the case of Peter, since peter does not show this defect this means his maternal grandfather was affected by this disorder.
Answer:
B. An egg cell and a sperm cell unite.
Explanation:
