Why is pluto said to be a dwarf planet

Assume that a student is given two different models of bacteria, with one model consisting of big bacteria and the other consisting of small bacteria. how can the student demonstate the theory of endosymbiosis using the models

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

In the ocean why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity