Human Biology

http://www.ck12.org Chapter 1. Human Biology

MEDIA

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1. How do external barriers help our immune system? What problems would we have if we did not have these
   barriers?


2. Where is mucus used as a barrier?


3. How do some bacteria aid our immune system?

Review

1. How does your skin protect you from pathogens?


2. How do helpful bacteria defend your body?