This post is furiosity's fault.

[conuly]

And if anybody can tell me why, they get cookies and juice.

Way back in my first stint in high school bio (I really, really, really hated that class. I'd've passed it the second time around if I hadn't been not attending school, though), we combined "blood types" with "basic mendelian genetics". So we learned that human blood type has three traits. O is recessive, and the A and B traits are co-dominant. (We didn't discuss the Rh factor.) So if you are type O blood, that means you have an O trait from your mom, and one from your dad. If you're A, that's really type AO or AA. B is really BO or BB. And AB is what you get when you get an A trait from one parent and the B trait from the other. Simple, right?

Except I never understood where rare blood types fit in. This, I think, is why I never understood bio, because I knew enough of stuff they hadn't taught (because this was a freshman class) to get confused about the stuff they did teach. And Ms. Kaplan was a bitch. She told guidance that she thought I was crazy. But that's a different story.

Moving on, I finally looked it up! It turns out that blood types are way more complicated. Nobody is just A+ or B-. While everybody has some combination of the A, B, O, and Rh+ or Rh- traits, we've all also got other traits. Except most of them, it's very rare to be positive for that trait. Or something. Well, scroll down and they explain it in detail, with this lovely example of a full blood type: O Rh negative: D- C-E-c+e+, M+S-, Le(a-), K-, Fy(a+b-), Jk(a+b-) CMV-

I'm happy now.

Also, apparently the O blood type is only the most common among certain groups of people. Other groups have other common blood types.

And now I'm done.

Comments

[rachelkachel]

My chemistry professor told us the first day that the only way to teach general chemistry is to lie to you. Things are almost always more complicated than they tell you in class, but if they tried to go into detail, you'd never finish the course. Obviously, it applies to biology as well.

My mom told me that I was A+ because both she and my dad are. Having at that point learned some basic genetics, I protested that she didn't know that for sure (though probability was in her favor). But then in biotech we tested ourselves and apparently she was right.

I knew there were other factors, but I didn't realize there were so many of them! That's crazy.

[deceptica]

Heh, our chemistry professor told us something similar when we were discussing the structure of atoms. I don't remember his exact words, but they were something like: "This is not how an atom looks. However, it works for what we want to do here, so we'll use that model anyway."

As for that blood article, I thought it was quite interesting! My mother always used to tell me that my brother had some sort of rare blood group... supposedly the blood he donates is categorized differently than what we would get if he needed a transfusion. Or something. I still don't really get that.

All I know is that I'm B-, which is rather uncommon here, but unfortunately I'm so low on red blood cells myself that I couldn't give blood even if I wanted to.

Reposted because of a typo.