International A Level Biology / Microbiology

How pathogens enter and how the body keeps them out revision notes

Edexcel International A Level Biology (YBI11), chapter 17: Microbiology, specification point 6.7. Part of the full course.

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Pathogens enter through thin or broken body surfaces, while non-specific barriers help stop them reaching tissues and multiplying. Knowing the difference between a pathogen and an infection, and explaining how each barrier works, helps you give precise exam answers.

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