Final answer:
The Rhesus factor got its name from the rhesus macaque, a primate whose blood is similar to humans. The Rh factor is a blood group system with many different types of erythrocyte antigens, and the most significant one is the RhD antigen.
Step-by-step explanation:
The Rhesus factor got its name from the rhesus macaque, a type of primate that was used in research and whose blood is similar to that of humans. The Rhesus (Rh) factor is a blood group system that includes many different types of erythrocyte antigens. These antigens are proteins, and the most significant one is called the RhD antigen.