help with what? there is nothing to answer
 
        
             
        
        
        
<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.
        
             
        
        
        
He observed 15 different finch species that originated as one ancestral bird. all differing in body shape, beak size, and mating habbits
        
             
        
        
        
Consumers. we are on top of the food pyramid being lead consumers
        
             
        
        
        
D.Blood pressure is highest in the arteries farthest away from the heart.