Question

Why are human males more likely to suffer from X-linked disorders that are caused by a recessive allele?

O males are hemizygous
O male hormones increase the genetic effect
O males cannot inherit any alleles from their mother
O males do not have any X chromosomes

Answer 1

Human males are more likely to suffer from X-linked disorders because they have only one X chromosome, making them hemizygous, and therefore any recessive allele on the X chromosome will be expressed, whereas females with two X chromosomes must have two copies of the recessive allele to express the disorder. Therefore correct option isA

Step-by-step explanation:

Human males are more likely to suffer from X-linked disorders that are caused by a recessive allele because males are hemizygous for the X chromosome. This means that males have only one X chromosome and thus only one allele for any X-linked trait. If this allele is recessive for a disorder, there is no corresponding allele on the Y chromosome to mask its effect, so the disorder will be expressed. In contrast, females have two X chromosomes, so they must inherit two copies of the recessive allele, one from each parent, to express the disorder. This makes the presence of recessive X-linked disorders like color blindness, hemophilia, and muscular dystrophy much less common in females, who more often are carriers without expressing the disorder.