The immune system is the bodies defense against invaders and is located in all body tissues with concentration in the mucosal surfaces and skin.
Answer:
B: <em>mitochondria produce the water from oxygen and the chloroplast produces oxygen from water.</em>
Explanation:
<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
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cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
Some advances is that organelles, cells, and the difference between the cells of a plant and a cell of an animal. This was an advance because not only did we discover new things but we learned how or body functions with them and how they work. Hopefully you got what you were looking for. :)
