Question

A father possesses an X-linked disorder. What is the chance that his son will inherit this genetic abnormality from the father?

Answer 1

Answer:

Option B

Explanation:

A father genotype for male sexuality is X'Y

Since he possess an X - linked disorder, thus in case if it is crossed with a mother with XX genotype

Thus, X'Y * XX

X'X, X'X, XY, XY

Thus, it is clear that a male child will carry Y chromosomes from his father and X chromosome from her mother. Thus, in order to have X-linked disorder, the male child must receive an affected X allele from his mother.

Hence, the probability of son inheriting an X-linked disorder from his father would be zero.

Option B is correct

Answer 2

X-linked disorder is a recessive autosomal disorder, which means that

There is a 1 in 4 chance (25%) of having a child who is unaffected.

There is a 1 in 4 chance (25%) of having a child who is affected by the condition. These children have two copies of the gene that do not work correctly.

There is a 1 in 2 chance (50%) of having a child who is a carrier of the condition.  These children have one working copy of the gene and one copy of the gene that does not work correctly.