Final answer:
Type O blood individuals are universal donors due to the absence of A and B antigens on their RBCs, enabling them to donate to any blood type. Type AB individuals are universal recipients because their blood lacks anti-A and anti-B antibodies.
Step-by-step explanation:
People who have type O blood are considered universal donors because they have no A or B antigens on their red blood cells (RBCs). This absence of A and B antigens means that their blood can be given to individuals with any ABO blood type without causing an immune reaction. However, type O blood contains both anti-A and anti-B antibodies, which means that individuals with type O blood can only receive type O blood. On the other hand, individuals with type AB blood are known as universal recipients because their blood lacks anti-A and anti-B antibodies, allowing them to receive blood from any ABO blood type.