What Is the role of antibodies in the human body?

Protection

Explanation:

Antibiotics play a very important role in the immune system. Whenever antigen or foreign particle enters in the body, B-lymphocytes identify that antigen and produce antibody against that specific antigen. Which kills that antigen. It also has another very important role, as whenever the next time the same antigen enters in body, the body already has antibodies against it. And kill that antigen immediately.

from the original order (top to bottom) the new order will go

1 (founder)

4 (hawk)

2 (mutate)

3 (next generation)

the endomembrane system i think