The answers could be vasodilation and vasoconstriction (respectively) if that’s what u are studying.
<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.
Competition factor are the species of birds responding to in the environment. Thus, the correct option is B.
<h3>
What is competition?</h3>
If numerous bird species eat on the same tree species, there will be fierce competition for food. As a result of the competition, each species will seek out a certain portion of the plant to feed on, most likely the part of the plant where it will be easiest to outcompete the competitors for food.
As a result, we may deduce that the right response is "They have evolved to diverse niches as a result of competition."
For more information regarding competition, visit:
brainly.com/question/15525466
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Answer:
In cellular biology, active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient.
Explanation:
I hope I helped
