Question

why are ab group people called universal recipients scientific reason? and why are o positive people called universal donars ?

Answer 1

Ab blood group people are considered as universal recipients because this blood group has no anti-bodies hence it can receive blood from all groups.
Whereas blood group O people have no antigens but have antibodies; hence they can donate blood to all blood groups but accept blood only from people having O blood group.
Hope i helped u:)

Answer 2

As v speak about universal recipient/universal acceptor is a blood type who has an AB blood group . They can receive "red "blood cells of any ABO with no risk of a serious hemolytic transfusion(Blood transfer) reaction due to ABO ///But there is one more factor's v have to consider is while transfusion is Rhesus "RhD+ or RhD- "There are 5 main "Rhesus blood group system" antigens present (may b or may not b)in the blood(C, c, D, E, and e), which are other antigens.But v only consider mainly on Rh factors .// U may aske What this means is that if someone is Rh D negative c't transfuse to other factors .yes they can receive a transfusion of Rh D negative to the RhD positive blood once. After that first exposure, their body may create antibodies that would attack Rh D positive blood, when they exposed to Rh D positive/negative blood once they c't receive once again if they recive they have a much higher chance of a allergic reaction.