Answer:
Rh factor
Step-by-step explanation:
Rhesus (Rh factors) is a blood group system. There are 36 blood groups and Rh is one of them. Rhesus is a protein that is present on the surface of the red cells of the blood. It is transferred in generations genetically. It is a dominant trait. If a person is Rh-positive that's mean it has a genetic makeup like this DD or Dd. And if a person is Rh-negative than it's genetic makeup is dd.