I see half of it and what are you working on?
The answer to this question is Homeostasis <span />
The distribution of living things is biogeography. bio means living and geography means location
After the macrophage fails the Helper T Cell stimulates the B cells (create antibodies) if pathogen is extracellular and Cytotoxic T Cells (killer T cells, release perforin) if pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
<span>Hope that's helpful.</span>
