nucleolus organizer vs nucleolar organizer

nucleolus organizer and nucleolar organizer both are nouns.

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

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

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

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

nucleolus organizer (noun)	nucleolar 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