HEREDITY
LAW OF DOMINANCE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
100%
|
|
|
75%
|
|
|
50%
|
|
|
0%
|
Detailed explanation-1: -For a child to inherit PKU, both the mother and father must have and pass on the changed gene.
Detailed explanation-2: -If both of a child’s parents are carriers, there is a 25% chance that each parent will pass on the normal PAH gene. In this case, the child will not have the disorder. Conversely, there also is a 25% chance that the carrier parents will both pass along the mutated gene, causing the child to have PKU.
Detailed explanation-3: -In the case of PKU, if both parents are heterozygous for the gene, there is a 1 in 4 chance that they will produce a child with the disease.
Detailed explanation-4: -Mutations in the PAH gene cause phenylketonuria. The PAH gene provides instructions for making an enzyme called phenylalanine hydroxylase . This enzyme converts the amino acid phenylalanine to other important compounds in the body.