Question

How is an adaptive defense initially primed?

a.Antibodies bind to surface markers of a foreign cell
b.Complement proteins identify a cell as foreign
c.By way of the clonal selection of effector cells
d.Upon exposure to a foreign antigen

Answer 1

The adaptive defense is initially primed upon exposure to a foreign antigen. It involves the recognition of the antigen by antibody presenting cells, followed by the activation of helper T cells and the production of specific antibodies.

Step-by-step explanation:

The adaptive defense is initially primed upon exposure to a foreign antigen. When an antigen enters the body, it is recognized by antibody presenting cells (APCs) such as macrophages. The antigen is then processed and presented on the cell surface with Major Histocompatibility Complex (MHC) proteins. This presentation activates helper T cells, leading to the clonal selection of effector cells that produce specific antibodies against the antigen.