Assertion: prion's characteristic | /r/HasProperty | necessary criteria
Facets:
value: generally
type: MANNER
value: for “life”
type: PURPOSE
Source sentences:
text: Viruses are considered by some biologists to be a life form, because they carry genetic material, reproduce, and evolve through natural selection, although they lack key characteristics (such as cell structure) that generally are considered necessary criteria for “life”, Because they possess some but not all such qualities, viruses have been described as "organisms at the edge of life", and as replicators.