Question

which is the definition of a sex - linked trait?
○ a trait that is coded by a gene located on a sex chromosome
○ a trait usually inherited with another trait on the same chromosome
○ a trait that is shared by siblings of the same gender
○ an allele that is inherited from a particular gender

Explanation:

A sex - linked trait is defined by a gene on a sex chromosome. Traits usually inherited with another on the same chromosome refer to linked genes (not sex - linked). Traits shared by same - gender siblings could be due to various factors (not specific to sex - linked). An allele inherited from a particular gender is not the definition of a sex - linked trait. The key is the location of the gene (on a sex chromosome) for a sex - linked trait.

Answer:

a trait that is coded by a gene located on a sex chromosome