Chapter 13

5. Any substances that can trigger a response from a B or T cell.
6. Host proteins that display antigen fragments on the cell surface for T cell recognition.
7. The deliberate introduction of selected antigens into the body to forcefully induce a memory response.
10. T cells that directly destroy infected or cancerous cells.
11. Long-lived immune cells that "record" information to fight a specific pathogen if it returns.
12. The specific, small part of an antigen that binds directly to an antigen receptor.
14. The primary white blood cells (B cells and T cells) responsible for the adaptive immune response.
15. The branch of adaptive immunity where antibodies defend against infection in body fluids.

1. A receptor on T cells consisting of alpha and beta chains that recognizes antigen fragments.
2. A slower, vertebrate-only defense that provides highly specific recognition of pathogens.
3. Specialized B cells that actively secrete antibodies during an immune response.
4. (Immunoglobulin)A soluble form of the BCR secreted by B cells to mark pathogens for elimination.
8. A Y-shaped protein on B cells used to recognize and bind to specific antigens.
9. Cells(APCs )Cells (like macrophages and B cells) that internalize and display antigen pieces to T cells.
13. Cells that detect pathogens and "conduct" the immune response by activating other immune cells.