How do X-linked traits differ from Y-linked traits?

X-linked traits are found on the X chromosome and can be inherited by both sexes, while Y-linked traits are only inherited by males.

X-linked traits are those that are associated with genes found on the X chromosome. Both males and females have X chromosomes, so both can inherit these traits. However, because males only have one X chromosome (inherited from their mother), they are more likely to express a recessive trait linked to the X chromosome. This is because they do not have a second X chromosome to potentially carry a dominant allele that could mask the expression of the recessive one. Examples of X-linked traits include colour blindness and haemophilia.

On the other hand, Y-linked traits are associated with genes found on the Y chromosome. Only males have a Y chromosome, which they inherit from their father, so only males can inherit Y-linked traits. These traits are always expressed in males, as there are no corresponding genes on the X chromosome to mask their expression. This means that Y-linked traits are passed directly from father to son. Examples of Y-linked traits include certain types of male infertility and the presence of a hairy ear rim, a rare condition known as hypertrichosis.

In summary, the main difference between X-linked and Y-linked traits is the chromosome they are associated with and, consequently, who can inherit them. X-linked traits can be inherited by both sexes but are more likely to be expressed in males, while Y-linked traits can only be inherited and expressed by males.