Question

Duchenne muscular dystrophy is an X-linked recessive disorder.

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What is the probability that a female offspring of the cross that is shown above would have a recessive allele for Duchenne muscular dystrophy disorder?
0 percent
25 percent
50 percent
100 percent

Answer 1

The answer is:

100 percent

Answer 2

Option D

Step-by-step explanation:

Given -

Duchenne muscular dystrophy is an X-linked recessive disorder.

The mother is heterozygous recessive for the Duchenne muscular dystrophy.

In this case if X' represent the affected allele, the genotype of affected female would be XX'

Also, the father is unaffected but is the carrier of recessive affected allele. Hence, Genotype of father would be X'Y

Cross between XX' and X'Y would give the following offspring -

XX', XY, X'X', X'Y

All the female offspring will have recessive allele for Duchenne muscular dystrophy disorder

Hence, the probability of a female offspring with recessive allele for Duchenne muscular dystrophy disorder will be 100 percent

Hence, option D is correct