Answer:
25%
Explanation:
Let's assume that the recessive allele "p" imparts diseased conditions in the homozygous genotypes. The genotype of each of the carrier parents would be "Pp". A cross between Pp and Pp would produce progeny in the following phenotype ratio=
Pp x Pp= 3/4 Normal : 1/4 Affected.
Therefore, there are 1/4 or 25% chances for this couple to have a child with PKU.
The metric system is an alternative system of measurement used in most countries, as well as in the United States. The metric system is based on joining one of a series of prefixes, including kilo-, hecto-, deka-, deci-, centi-, and milli-, with a base unit of measurement, such as meter, liter, or gram. (got the answer from google hehe)
<span>It's the third option.</span>