Sure. For some people, explaining biological reasons for transness is something they feel knowledgeable about and comfortable with doing.

My personal preference is just to start with the assertion: Everyone should be allowed to transition if they want to, and everyone else should respect their gender! I hope that this starting point can be enough for most people to find their way to compassion. (Realistically, I never get to the part about explaining biology, because that just isn't my thing.)