nucleolar organiser vs nucleolus organizer

nucleolar organiser and nucleolus organizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
nucleolar organiser	Yes	No	No	No
nucleolus organizer	Yes	No	No	No

As nouns, nucleolar organiser and nucleolus organizer are synonyms defined as:

nucleolar organiser and nucleolus organizer: the particular part of a chromosome that is associated with a nucleolus after nuclear division

Other synonyms of nucleolar organiser include nucleolar organizer, nucleolus organiser.

nucleolar organiser (noun)	nucleolus organizer (noun)
the particular part of a chromosome that is associated with a nucleolus after nuclear division	the particular part of a chromosome that is associated with a nucleolus after nuclear division