How are antigens recognized by immune system cells?

And give a detailed description! scientist observes the boundary between two tectonic plates for a decade and finds that no new volcanoes have formed over the course of her investigation. does this result support the theory of plate tectonics? why or why not?

With the word calcite wich completes the analogy mineral, erosion, marble, or aragonite

What tool do geneticists use to predict the outcome of genetic crosses? a.karyotype b.punnett square c.centrifuge