Because you cannot test it or observe it.
A scientific theory are created through the scientific method, in the scientific method you need to be able observe it and experiment.
Answer:
polar regions and nonpolar regions
Explanation:
if right braniliest? I only need one more
A Lipid because it's a fresh osmosis they are always active
<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.
