Final answer:
The X and Y chromosomes determine gender in humans. Females have two X chromosomes (XX) and males have one X chromosome and one Y chromosome (XY). Sex-linked traits are located on genes on the sex chromosomes.
Step-by-step explanation:
The X and Y chromosomes are the chromosomes that determine gender. In humans, females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). Sex-linked traits, such as eye color, are located on genes on the sex chromosomes.