Let's say that matters, because yes sometimes it does. Blood groups. What we can / can't digest. Genetics. But sometimes, it doesn't. We wear clothes, take drugs, go to space, have surgery. Human lifespan (eta, average, ish) has nearly doubled in the last 5000 years and we do all kinds of stuff that goes against 'biological truth'. It sustains us, improves us, and we're evolving with it. Capitalism aside, it's generally a good thing.
But you'd draw the line at sex and gender, male shall be masculine and female shall be feminine. Regardless of sexuality (I'll do you the courtesy of assuming youre not just homophobic) the 'biological truth' behind gender is sacrosanct - why? Why is your line there? (with respect to
CNT36 who's already asked but not been answered)