Which gammaproteobacteria are facultatively anaerobic

What statements describe a host organism?

Which of the following statements about protists are true? a.they are typically found in moist environments. b.they are all unicellular. c.they have a nucleus. d.they are all multicellular.

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.