Final answer:
Females are more likely to be carriers of X-linked traits, and males are more likely to express them. Option a
Step-by-step explanation:
The correct answer to the question is: A) Females; males. In the context of X-linked traits, females have two X chromosomes and thus are more likely to be carriers of these traits without necessarily expressing them. This is because they can possess one recessive allele and one dominant allele for the trait on their two X chromosomes, where the dominant allele can mask the expression of the recessive one.
Males, on the other hand, have a single X chromosome paired with a Y chromosome, so if they inherit a recessive allele for an X-linked trait on their X chromosome, they will express the trait since there’s no second X chromosome to potentially have a dominant allele to mask the recessive one. Hence, X-linked disorders such as red-green color blindness and hemophilia are more frequently observed in males. Option a