predominant vs dominant

predominant is not a noun while dominant is a noun.

Word	Noun	Adjective	Verb	Adverb
predominant	No	Yes	No	No
dominant	Yes	Yes	No	No

As adjectives, predominant and dominant are synonyms defined as:

Other synonyms of predominant include prevailing, prevalent, rife.

predominant (noun)	dominant (noun)
	an allele that produces the same phenotype whether its paired allele is identical or different
	(music) the fifth note of the diatonic scale

predominant (adjective)	dominant (adjective)
having superior power and influence	exercising influence or control
most frequent or common	(of genes) producing the same phenotype whether its allele is identical or dissimilar
	most frequent or common