okay.. if you know that the sharingan is recessive then how are you possibly thinking that there is a 25% chance of a baby? If the gene is recessive, then Sasuke has to have ss (non-sex linked) , or sY (sex-linked) because otherwise the dominant gene (having no sharingan) will dominate over the recessive sharingan gene. (And yes, when you are ss, the s is considered dominant only because it is dominant compared to the other gene, but when compared to the dominant gene (having no sharingan), it is recessive) And he has to have kids with a non-uchiha girl (cuz the clan was wiped out) and since having no sharingan is dominant and she has no sharingan gene at all, she has to be SS ( first S coming from having no sharingan and she cant be a carrier cuz she has no uchiha blood ). So when they have kids, it can only be: Ss, Ss, Ss, Ss -having NO sharingan. And when its sex linked it can still only be : SY x 2(no sharingan male), Ss x 2(no sharingan female). So you got the definitions down, but whenever you put it into actual genotypes, it wont work.