Red gave blood today. As Red was sitting around filling the bag, he began to wonder about why we have different blood types. Why does every body accept O neg? Why blood poisoning? What makes blood different types?
I can’t answer why different blood types exist, but I’ll give a shot on your question about type O being OK for all transfusions.
The “A” and “B” refer to proteins in the red blood cell membrane. These proteins can cause an allergic reaction to anyone who doesn’t naturally produce them. If you have Type A blood your body would treat type B blood as foreign and reject it. If you have type AB, then your body’s immune system already recognizes and accepts both the A proteins and the B proteins, so you can accept both types of blood. Type O blood doesn’t have either of these proteins, so no matter what your blood type is, type O won’t cause any immune reaction.
The + and - refer to the presence of a RH antigen. Same story. If you are naturally Rh positive, then you can accept Rh positive blood, but if you are naturally Rh negative, then your body treats the Rh antigen as an intruder. So O+ blood would be accepted by anybody based on blood type but would be rejected by Rh negative people. 0- blood, though, doesn’t have any antigens to produce a reaction.
Blood is part of the immune system. Different pathogens require different antigens. Different geographic locations have different pathogens.
Mutation and natural selection like everything else.
Im trying to start a new type of hate group based on blood type rather than race or religion. Anyone want in?
Those crummy A’s and B’s think they’re better than anyone else. Just wait, we O’s will show them.
I’ve always heard the reason we have different blood types is because diversity is an evolutionarly advantage.
For example, if hypothecially, a virus arose or mutated so that it would kill everyone it encountered with the A+(or B-, etc) blood type. If everyone has that blood type, everyone that the virus comes into contact with is essentially screwed. If the society where this society first infects if isolated, it will just kill the society. However, if such a society was like ours, and was very interconnected, well, kiss the entire species (or an extremely large perchentage of it) goodbye.
With 8 different blood types (A, B, AB, O, then + or -), any such virus would only kill perhaps 1/8 of any given population (I’m guessing. I know the types are not equally distributed. I know 0 is most common and AB is least).
And even though the above scenario is far-fetched(I’m just giving an example), I think it does have something to do with Diease suspectibility(or the fact that having mutiple blood types isn’t an evoluntionary disadvantage as to impair the surivival of the species).
Aren’t the 0’s the most numerous, or just 1/4?
I know AB is supposed to be rare, but they can recieve from anyone, so it doesn’t matter. But if O can only recieve from another O, doesn’t that necesstiate there be a lot of O’s to make up for it?
Wonders because of his O’ness.
From recollection from A-Level (16-18yrs) Biology, there are, in fact, many many more types of blood. A, B, O and rhesus are the main factors, but there are also many other antigens that relate to blood typing. Normally these others don’t come into play, but those with serious illness might be affected by other antigens so these are taken into account in these cases.
Sure, sign me up! I assume that us A+ type will be running the show while we use those lowly O type for spare fluids?
Do the letters stand for something? Why not just have types A, B and C?
Type O blood (both + and -) accounts for about 46% of the general population (with O+ representing about 39% and O- the other 7%). See here for various charts and facts and such.
As for why different blood types in the first place, your first post is probably correct: more variety = a good thing. That, and the fact that no given type is particularly disadvantageous (or more advantageous) than any other.
Blood types in most animals are polymorphic, meaning that there are many varieties within a population. Aside from the “common” ABO and Rh factors, there have been at least 600 other antigens identified in humans; an alternate “MN” blood grouping also exists, though it is used less commonly than ABO typing.
There is potentially specious reasoning here. Diversity is an evolutionary advantage but different blood types don’t arise because of it. Tendency to mutate and sexual reproduction cause the diversity. When scientists speak of diversity being advantageous, they typically mean within a population. Blood type, like race, is really extrapopulation diversity. In other words, we don’t have different races because diversity has been selected for but because race attributes were more suitable to those specific populations.
Regarding my hate group. All along I thought I was a member of the elite AB. A fateful trip to the hemotologist revealed that I was in fact, what I once thought was a lowly, primitive O. I renounce my blood typism and will tell my story on a Maury Povich show to air in a few weeks. It is a heartwarming tale of enlightenment. There will also be some kid who can’t go out in the sunlight and another who is getting old really fast.
I’m AB Positive.
I’ve heard that, in Japan, blood types are used for fortunetelling or sexual compatabilty “testing”, like horoscopes.
If any cute Japanese girls are lurking, compatable & interested, e-mail me. 
I’m AB Positive.
I’ve heard that, in Japan, blood types are used for fortunetelling or sexual compatabilty, like horoscopes.
If any cute Japanese girls are lurking, compatable & interested, e-mail me.
Evidently so.
Well, the A’s made the playoffs, while the O’s sat on the cellar steps. Who are the B’s?
Nitpick: They are not proteins. But rather sugar molecules that are attached to the surface proteins. Or to be completely exact, a sugar molecule that’s attached to a chain of other sugar molecules that are attached to the surface proteins. There’s a different sugar for type A than for type B with type O not having any sugar in that particular spot.
Attrayant – The A and B are generic letters for the factors prestent. It could have been X or Y, but it wasn’t. I assume that A was the first one identified, and that if a third had been identified, it would have been called C.
O signifies a zero, or no factors present, at least not the AB factors. I’m O negative, so I’ve got no commonly tested factors.
The Rh factor wasn’t called C because it usually doesn’t cause enough of a reaction to be dangerous the first time someone is exposed. It’s the second exposure that’s the killer. It was called Rh, I think, because it was first identified in rhesus monkeys.
I’ve alway thought that was kind of weak, but it’s a case of “It’s good to be the Discoverer”.
Ah. So O-negative should be spoken as “zero-negative”?
No, it really is designated as an “O” (“oh”), not a “0” (“zero”).
Incidently, here is a site which lists the various blood groups (including, and aside from, the ABO / Rh groups). You can click on the ISBT (Inernational Society of Blood Transfusion) numbers for more information. Here you can find a handy chart showing how many antigens are involved with each blood group system.
And here is a site for blood groups for dogs and cats, and one for horses.