Give two ways in which white blood cells destroy disease-causing micro-organisms.

Macrophages and neutrophiles destroy microorganisms through phagocytosis (engulfing them whole) and are found in the interstitial fluid (outside of the blood stream and cells). The pathogen is drawn into the macrophage where enzymes such as lysozyme kill the pathogen. 

Lymphocytes do not attack directly but instead, they recognize that the cell has become infected by a virus and release antibodies that tags to invader by binding to the antigen molecule. This triggers the mechanism that destroys the invader.

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