Two linked defence systems
Two linked defence systems
A pathogen is a microorganism or virus that causes disease. The immune system deals with pathogens using non-specific defences that act broadly and specific defences that target one particular antigen.
Step-by-step lessons on Edexcel A A Level Biology Non-specific and specific immune responses. Each one builds up to exam-style questions. Build a strong foundation in cell biology and biochemistry early on, since later topics on genetics, ecology and physiology all draw on these core concepts.