Respuesta :
Most likely due to the fact protists or protozoas causes diseases such as malaria and some are parasitic. And the major problem is they're microscopic making them a misfit for us and other organisms.
It's one of these, but you didn't put them so no one can help now...
They are very diverse and contain animal-like, plant-like and fungal-like protists
They contain some parasitic protist but they also contain some beneficial protists
They can be found everywhere in the world.
They have a wide variety of uses.