Question

why are sex - linked disorders more common in males? males only need to inherit one copy of the allele on a sex chromosome for it to appea sex - linked disorders are more common in females. sex - linked disorders are dominant.

Explanation:

1. Analyze the first option: Males have XY sex chromosomes. For X - linked disorders (a common type of sex - linked disorder), since males have only one X chromosome, if they inherit one copy of the allele for the disorder on the X chromosome (or Y - linked, but X - linked is more common), the disorder will be expressed. Females have XX chromosomes, so they need two copies of the allele (for recessive X - linked disorders) to show the disorder.
2. Analyze the second option: Sex - linked disorders (especially X - linked recessive) are more common in males, not females, so this option is incorrect.
3. Analyze the third option: Sex - linked disorders can be recessive or dominant. The key reason for higher prevalence in males is the single X chromosome in males, not that the disorders are dominant. So this option is incorrect.

Answer:

A. Males only need to inherit one copy of the allele on a sex chromosome for it to appear