Jump to content

genetics


mutale
 Share

Recommended Posts

  • 2 weeks later...

I am not sure what your question was:

 

In case you wanted the term to be explained:

Actually in most other languages the system is called AB0 (a zero) and not ABO (an O).

Humans have either the A antigen, the B antigen or no antigen (this is why it is called zero in most other languages).

So the term "O-positive" is a bit strange (means you positively have nothing :) ).

 

In case you wanted to know why the majority has O:

I do not know :), but maybe somebody else in the forum knows...

Edited by Jens
Link to comment
Share on other sites

i would hazard a guess that having no antigen is cheaper (in resources) then having an antigen

 

also mothers occasionally produce IgG antibodies against foetal blood, which cross the placenta (may cause miscarriage), and since O type has no antigens it is the "safe" blood type

 

don’t quote me on this though its just a guess...

 

 

Link to comment
Share on other sites

The "positive" or + designation refers to the presence of "Rhesus factor", a certain kind of protein in the membrane of most people's red blood cells - O+ blood has the antigen, and sensitized people of any ABO type who lack it (such as Rh- people who have been pregnant with an Rh+ fetus, or received a previous transfusion of Rh+ blood) will suffer adverse reactions to transfusions of O+ blood (or any other Rhesus positive blood regardless of ABO type) which can be severe.

 

Rh- mothers will often create an immune reaction against (and inside) second or subsequent Rh+ fetuses (the first one sensitized their immune system, like a vaccination), and this special concern is one of the differences between Rhesus factor and the blood type factors of the ABO system.

 

The persistence of Rh negative populations (mostly among northern Europeans and their descendants) in a world of people mostly Rh positive, despite this targeted risk to reproduction, indicates by presumption the likelihood of advantage of some kind.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.