Thank you for reporting, we will resolve it shortly
Q.
A woman has an X-linked condition on one o f her
X-chromosomes. This chromosome can be inherited by
Principles of Inheritance and Variation
Solution:
In the given problem, the woman has an $X$-linked condition and she can transmit the carrier allele to both her son and daughter. The resulting son will affected because $X$-linked disorder always affect males as males contain a single $X$-chromosome. The daughter offspring will be a carrier, but not diseased because females are affected by $X$-linked disorder in homozygous recessive condition only, i.e. two recessive alleles are required.
Hence, out of the $4$ offspring possible $25 \%$ of sons are diseased and $25\%$ are normal. Similarly, $50\%$ daughters normal out of which half are carriers.