So this is stuff that I've learned about biology that relates to being trans and that "biological sex" you hear so much about nowadays. This became somewhat of a special interest of mine after I came out as trans, and learning it has helped me feel a lot better about my body and what's possible in the future. This stuff is relevant no matter which direction you're transitioning in, or even if you're not transitioning at all. There's going to be discussion of genitalia, and also, while this stuff makes me feel better, I've heard that it makes some others feel worse. If you're the kind of person who's going to be uncomfortable with those things, turn back now.