<span>Punctuated
Equilibrium/ Equilibria proposes that once species appear in the fossil record,
the population will be in the state of
little or absent morphologic change. This is called a state of stasis. The
theory further proposes that the population is confined to infrequent and
geographical rapid events when significant evolutionary change happens. The parent species will the split into two
distinct species. This process if called cladogenesis.</span>
Arthritis is a joint disorder involving joint inflammation.Pain is often localized to only the affected joint. Osteoarthritis is a wear and tear type of arthritis often affects aging population affecting joints in hands,knees and lower back. Heberden's node is an example and develops around middle age thus Wendell might have this.
The answer to this one is D
<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.