I can see all sorts of vagueness in your language (e.g., "biological factor"). The reason you seem to be hesitant to write out a definition of DNA I think is because you know that it is, in general, quite difficult to specify the precise perimeters of categories that we usually implicitly assume. It's quite hard even for things as simple as "water". It's really the same thing with male and female and all sort of other categories of macroscopic things.

Males and females have "specific characteristics" as you use here, they don't seem like particularly special categories and have some of the same issues as "DNA", "water", "tail" etc.