What term describes one-celled microorganisms that exhibit characteristics of both plants and animals?

The term that describes one-celled microorganisms exhibiting characteristics of both plants and animals is indeed "Protozoa." Protozoa are unicellular organisms that can be found in a variety of environments and display features typical of both plants (such as some being able to photosynthesize) and animals (such as being able to move and ingest food). They are part of the kingdom Protista and are known for their diverse forms and behaviors.

Bacteria are also one-celled microorganisms, but they do not exhibit the same dual characteristics of plants and animals. Instead, they are classified as prokaryotes and lack a nucleus. Viruses, on the other hand, are not considered living organisms as they require a host cell to replicate and do not possess both plant and animal features. Fungi are multicellular or single-celled organisms that absorb their nutrients from their environment, distinguishing them from both plants and animals as well.