Saliva - Found in the mouth and contains chemicals (enzymes) which kill bacteria/pathogens, Tears - Found in the eyes and contains chemicals (enzymes) which kill bacteria/pathogens., Skin - Prevents entry of microorganisms, Mucus - Traps dirt and pathogens, Stomach acid - Low pH kills harmful microorganisms, 'Good' bacteria - Out competes pathogens preventing them from growing,

Match up - first line of defence

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