GCSE›Edexcel GCSE Biology›Mind mapsDefence Against DiseaseEdexcel GCSE Biology: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsBarriersPhysical: skin, mucus, ciliaMucus traps pathogens, cilia move it awayLysozymes break down bacterial cell wallsHydrochloric acid in stomach kills pathogensImmune responseAntigens trigger antibody productionAlso makes memory lymphocytesSecondary response is faster and largerAntibodies are specific to one antigenImmunisationInactive or dead pathogen givenTriggers antibodies without causing diseaseHerd immunity: high uptake protects the unvaccinatedSide effects mild, not 100% protectionDefenceagainst diseaseAbAgAntibioticsInhibit bacterial processes, not host cellsNo effect on virusesCannot treat viral infectionsAseptic practicalAutoclave sterilises equipmentFlame the sterile loop before and afterDiscs on inoculated agar plateLarger zone of inhibition = more effectiveArea of zone = πr2\pi r^2πr2Exam tipsSecondary response: faster and more antibodiesSay mucus traps, cilia move itAntibiotics never work on viruses