Final answer:
Sex-linked genes are located on the sex chromosomes, primarily the X chromosome. They are inherited differently based on an individual's sex. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).
Step-by-step explanation:
Sex-linked genes are genes located on the sex chromosomes, primarily the X chromosome. These genes are called sex-linked because they are inherited differently based on an individual's sex. In humans, males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). Because males only have one copy of each X-linked gene, they are more likely to express the traits associated with these genes. Females, on the other hand, have two copies of each X-linked gene, providing a backup if one gene is defective or carries a recessive trait.