Question

pseudohypertrophic muscular dystrophy is a human disorder that causes gradual deterioration of the muscles. Only boys are affected, and they are always born to phenotypically normal normal parents. Due to the severity of the disease, the boys die in their teens. Is this disorder likely to be caused by a dominant or recessive allele

Answer 1

Answer:  recessive allele

Explanation:

The fact that it affects boys only it shows that its inheritance  follows  X-linked recessive pattern.

The sex chromosome for male is  XY and for female XX

.Therefore. the disorder is on the X=chromosomes of the father. Y chromosomes are smaller than X and weak, therefore they can not bear the allele of the disorder.  

However.if a female inherited  the allele of the disorder from the father. she can pass this trait to her son during fertilisation,