Doubt it, there was a girl I knew with an androgynous appearance that I could've sworn on my life was a guy. Bit of a surprise when I found out he was a she.
Some people have definite masculine or feminine faces, especially when combined with their hair style. Other people I can't tell one way or the other, even by looking at their entire (clothed) body.
I don't think so either. I know alot of guys that would make pretty girls and have been mistaken for a girl and I know girls that you would swear they were boys.
