What key feature distinguishes Y-linked traits from other inheritance patterns?

Y-linked traits are unique in that they are exclusively passed from father to son, meaning that only males can be affected. This is due to the fact that these traits are located on the Y chromosome, which is present only in males. When a male carries a Y-linked trait, he will pass it directly to his male offspring.

This mode of inheritance ensures that any traits linked to the Y chromosome will not be expressed in females, since they do not possess a Y chromosome. Therefore, the presence of Y-linked traits provides certain diagnostic cues for determining paternity or lineage through the male line. This key feature sets Y-linked inheritance apart from other inheritance patterns such as autosomal inheritance, where traits can affect both genders and can be passed on through either gender, or mitochondrial inheritance, which is only maternal.