<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.
Sound waves enter the outer ear and pass into the ear canal where the waves cause the eardrum to vibrate.
Hope this helps you.<3
Answer:
what do u need help with?
Answer:
The correct answer will be option-D.
Explanation:
Photosynthesis proceeds in two stages: light-dependent and light-independent reaction.
The light-dependent begins when the chlorophyll pigment of the photosystem absorbs light energy. This absorption causes the excitation of the electrons provided by the chlorophyll molecule.
The excited electrons accepted by electron acceptor molecule from reaction center and a chain of electron flow begin called electron transport chain.
This transport of electrons creates a scarcity of electron in photosystem which causes splitting of the water molecule as a result of which oxygen gas is released.
Thus, option-D is the correct answer.
