Until recently, human beings have long been considered sexually dimorphic, consisting of male and female sexes. This binary view of human sexuality is now being challenged by those who espouse an LGBTQ/transgender ideology. In the push to force acceptance of their beliefs on the public at large, transgender advocates claim there is a spectrum of human genders and that individuals can choose where they fall on that spectrum. They would also have us believe that individuals can change their sex via sex reassignment surgeries. These ideas are not based on biological realities. Biological sex is grounded in anatomy, physiology, and genetics. Here, I describe why—biologically—there are only two sexes (= genders) and why true sex reassignment is impossible.