Even though they work with just 1 and 0, the end result is based on a combination of such. On this same work, humans' genes combinate themselves in a total of 28 pairs which keeps multiplying to undergo the cells, the cells the organs, the organs the pluricellulal form.
When talking about reproductive cells, men cells (Spermatoz moides) can be either X or either Y, as long as ovules (female's cells) are only X. A combination of those cells, on our pair 28, defines our gender.
Pair 28 of our genetical code is the one that defines our gender. If it's XY, it'll be male. If it's XX, it'll be female. However, people isn't really like computers, since computers can never fall unless the people do it wrong, and errors appears on nature without the hand of the human. What about if there were a pair 29?
Some people lacks of the second X/Y , those are females who can't concept, because they lack of the gen that makes our hormones work. Other people got an extra gen, those are the XXY, men that can't have childs because the second gen of the pair 28 makes pair 29's first gen child organ not work properly.
But, we've talked about "genetical disorders" about what the gender genetical code relates, since those last 2 examples aren't complete on pairs.
What if there was a pair 29, and it was filled out? This, outside any possibilitie of look as imposible, is posible: It would be an hermaphodite, with a pair 28 XX and pair 29 XY.
Just one over 2000...
... i mean, hi!
hey~ect... 
