Question

both parents of a child are carriers of a recessive allele for a disorder. what is the probability of their child having the recessive disorder? a 0% b 25% c 50% d 100%

Explanation:

Step1: Determine the parents' genotypes

Let the dominant allele be \(A\) and the recessive allele be \(a\). Since both parents are carriers, their genotypes are \(Aa\).

Step2: Create a Punnett square

	\(A\)	\(a\)
\(a\)	\(Aa\)	\(aa\)

Step3: Calculate the probability

There are 4 possible genotypes (\(AA\), \(Aa\), \(Aa\), \(aa\)). The genotype \(aa\) (recessive disorder) occurs 1 out of 4 times. So the probability is \(\frac{1}{4}= 0.25 = 25\%\)

Answer:

B. 25%