ELI5- What are blood groups? Why do they differ from person to person? Why can’t a person of one blood group receive blood from a person of a different blood group?

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In: Biology

Answer 1

So I work in a lab and absolutely love this question cause a lot of people don’t understand how blood works. There’s a lot of other subgroups of blood also (ie. Duffy, luis, iI, Lutheran, etc.) But I won’t go into that, ill explain the 6 main ones. There’s A, B, AB, and O
Each blood type has antibodies on them, they’re little markers.
A blood types can’t have B blood types given to them because the A markers will see B markers and destroy them because they aren’t the same.
AB blood types have both markers on the cell so they can get A, B, AB or O, though you don’t want to give them just A or B blood but you can.
O blood doesn’t have any markers on the cells so they can be given to any blood type but can only get O blood type. That works basically because O has no markers on it so other blood types don’t have to destroy them but since other blood types do have markers on them they will be destroyed by the O blood (called an antibody response.)

Now for the other two important blood types, Rh. You can either be Rh positive or negative. Basically you either have little antibodies of Rh on your cell (postive) or no anitibodies on your cell (negative)

So if someone is B negative they can give to someone who is B positive and be ok. If someone is B positive and gives their blood to someone B negative their cells will be destroyed because the positive cells have the markers on them the negative cells don’t recognize. This is also why if a negative blood type mother has a positive blood type baby, the baby can die because the mothers blood recognizes it as foreign and will destroy the baby’s blood type (they have medicine to basically mask the babies blood from the mother)

Sorry if this is confusing, ill find a youtube video to source if you’d like it better explained, I did my best to explain it haha