Which macromolecule is primarily responsible for the inheritance of hemophilia from parents to their children?

Which symbol is used to label a male that expresses a sex-linked disorder on a pedigree?

Which allele combination represents a female who is heterozygous for a sex-linked trait?

How are alleles for sex-linked traits typically inherited in humans?

In cats, the gene for fur color is located on the X chromosome, with the allele for black fur (B) and the allele for orange fur (O) being codominant. Which of the following fur colors are possible in male cats?

In a cross between a homozygous normal female (XX) and a male affected by an X-linked recessive disorder (X^aY), why are there no affected females in the F1 generation?

In X-linked patterns of inheritance, which of the following is true?

Males are more often affected by X-linked traits than are females because:

X-linked recessive traits in humans (or in Drosophila) are observed most frequently in which group?