Not if there's 100%/0% and 0%/100%. Synonyms for Spectrum include Scale and Range. That 100/0 to 0/100 is the range. This ain't no Mobius Strip.
Don't think that hasn't been tried.
Two points that come into play: chromosome arrangements and that the vast majority of M>F transsexuals were raised as male.
As someone once told me:
Livin' The Dream...
DeeAnn