Mutualistic relationships is where both organisms cooperate and benefit from each other while predator prey relationships is just an organism hunting down another organism.
THE blood group AB is called the universal receiver because any other blood group can be compatible with this blood group this is due to the absence of anti-bodies in this type
while blood group O is called the universal donor because it is compatible with all blood groups due to the absence of antigen (A and B)
while blood group A receives blood from itself and O and donates blood to itself and AB thesamethinggoeswithbloodgroupB