nucleolus organizer vs nucleolar organiser

nucleolus organizer and nucleolar organiser both are nouns.

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

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

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

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

nucleolus organizer (noun)	nucleolar organiser (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