Q: An antigen is a macromolecule that reacts with components of what?


Read this paragraph and choose the correct option from the provided answers:

Figure 42.10 An antigen is a macromolecule that reacts with components of the immune system. A given antigen may contain several motifs that are recognized by immune cells. Each motif is an epitope. In this figure, the entire structure is an antigen, and the orange, salmon and green components projecting from it represent potential epitopes.

 Choices:

- circulatory system

- pulmonary system

- digestion system

- immune system


A:
immune system