Question

question 6
10 points
albinism is a recessively inherited condition. what is the probability that a child will be born with albinism if the childs mother is albino, the childs father has normal pigmentation, and the childs paternal grandmother was albino?
a 25%
b 50%
c 75%
d 100%

Explanation:

Step1: Define alleles

Let \(A\) represent the dominant allele for normal pigmentation and \(a\) represent the recessive allele for albinism. The mother is albino, so her genotype is \(aa\).

Step2: Determine father's genotype

The paternal - grandmother was albino (\(aa\)). Since the father has normal pigmentation, he must have received one \(A\) allele from his father and one \(a\) allele from his mother. So the father's genotype is \(Aa\).

Step3: Use Punnett - square analysis

Cross the mother (\(aa\)) and the father (\(Aa\)). The possible genotypes of their offspring are determined by the cross:

	a	a
a	aa	aa

The probability of getting an \(aa\) (albino) offspring is \(\frac{1}{2}\) or 50%.

Answer:

B. 50%