Question

1 - general science
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%
click the button or type the letter next to your answer.

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 (\(AA\), \(Aa\), \(Aa\), \(aa\)). Only \(aa\) results in the recessive disorder. So the probability is \(\frac{1}{4}= 25\%\)

Answer:

B. 25%