<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.
</span>
cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
Answer:
Anticodon. The anticodon region of a transfer RNA is a sequence of three bases that are complementary to a codon in the messenger RNA. During translation , the bases of the anticodon form complementary base pairs witht the bases of the codon by forming the appropriate hydrogen bonds.
I just had this answer but it hasn't been graded. I put 1. Meteor impacts, 2. volcanic gases and 5. Milankovitch cycles. I didn't put earthquakes because I wouldn't think it would affect the climate changing since they just affect ground movement.