Sex-linked inheritance is when an allele is linked to the X or Y chromosome, only functioning on that chromosome. How does this make a difference? A good example is color blindness. Color blindness is recessive and linked to the X chromosome. The reason it is much more common in males is that they only have one X chromosome, so if they get the allele they will be colorblind. A female, however, has two alleles so they both must have this trait in order to be colorblind.