A Level Biology Defence Mechanisms

This comprehensive A‑Level Biology resource covers the Defence Mechanisms topic from the AQA specification. It is designed as a high‑level comprehension activity with detailed revision notes, followed by 20 exam‑style questions and a full model‑answer mark scheme.

Topics covered:

The concept of immunity, including innate (non‑specific) and adaptive (specific) immune responses
Active and passive immunity, with examples such as maternal antibodies, infection and vaccination
T lymphocytes: T helper, cytotoxic, regulatory and memory T cells, including their roles in cell‑mediated immunity
B lymphocytes: clonal selection, clonal expansion, plasma cells and memory B‑cell formation
Self vs non‑self recognition, including MHC molecules, antigen‑presenting cells and pathogen‑associated molecular patterns
Negative selection, clonal deletion and mechanisms preventing autoimmunity
Coordination between non‑specific and specific defence systems (e.g., phagocytes triggering lymphocyte activation)
The roles of cytokines, perforin, granzymes, antibodies and the complement system
Autoimmune disease caused by failures in self‑recognition

What’s included:

A full Word document containing high‑quality revision notes and 20 A‑Level comprehension questions
A separate Word mark scheme with detailed model answers for each question
A glossary of key immunological terms to support independent revision

Perfect for:

A‑Level Biology (AQA) revision, in‑class comprehension tasks, homework and intervention
Developing high‑quality extended‑response exam technique