Described how sex - linked are expressed differently in males and in females?

Answer 1

In humans, females (XX) have two X chromossomes whereas males only have one. While most of one of the X chromossomes is deactivated in females it's still less likely for females to get an X-linked genetic disorder unless in double dose or a dominante gene. For males (XY), on the other hand, since they only have one X chromossome that isn't deactivated, one dose is usually enough to cause them to have the disorder, whether the gene is recessive or dominant. That's why males are way more likely to get such disorders than females. Hemofilia, daltonism and baldness would be three examples.

Traits linked to the Y chromossome will practically always manifest in males, and never in females. Hairy ears would be one example.