It's not that I don't understand what you're getting it. I also think race is poorly categorized.

Organs aren't matched by race, they are matched based on medical compatibility. While people from the same race may have a better chance of finding a match, there's absolutely nothing stopping an organ donation between races. 


Race is a social construct until you need an organ donation/transplant



Bell_curve

Not according to pretty much anyone who maintains demographic statistics.