Final answer:
Tolerance is the immunological unresponsiveness to self-antigens to prevent autoimmune reactions.
Step-by-step explanation:
The immunological unresponsiveness to self-antigens is called Tolerance. This means that the immune system does not mount an immune response against the body's own antigens or proteins. This is an important mechanism to prevent autoimmune reactions, where the immune system mistakenly attacks the body's own tissues.