Universal donor?

Question

i can't remember which one is the universal blood type is it o pos or o neg. who can donate to an o pos?

Answer 1

O negative is the universal donor.  O postive or O negative could donate to O+.  But they usually try to match it more tightly than that, so would go with the O+ donor.  O is not an uncommooon type, so it would not usually be hard to find an )+ match.

Answer 2

The ABO system is based on certain molecules that are presented on the surface of red blood cells. For those who are A, B or AB, they are those particular molecules on their surface, which means for those people, their immune systems will react against the ones that are not in their body, which is why an A individual cannot get a transfusion from a B individual. People who are O have neither A nor B, which means they have no molecules on their surface (this is a simplified version of the reality, but it's enough). These people are universal donors because when their blood is transfused into other people's body, there are no molecules on their surface to react with their immune system, regardless of whether they are A, B or AB. In addition, there is an additional molecule called Rh that is either present or absent in an individual (present = positive, not present = negative). An individual who is negative for Rh can donate to all other individuals (with and without). To put them together, O negative would be the universal donor. I hope that helps. Feel free to ask if you are still confused.