With the help of given pedigree, find out the probability for the birth of a child having no disease and being a carrier (has the disease mutation in one allele of the gene) in $F_3$ generation.

• Correct answer
  A

  1/4
• B

  1/2
• C

  1/8
• D

  zero

Solution

As in the $F_1$ generation the carrier female and non-affected (normal, not carrier) had affected male child that means the genetic disorder is sex-linked recessive. The consanguineous mating between female $\left(X^C X\right)$ and male $\left(X^C Y\right)$
Out of 4 child only one is carrier i.e. $\frac{1}{4}$.

Hence, the correct answer is option: 'A'.