physiologist vs biologist

physiologist and biologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
physiologist	Yes	No	No	No
biologist	Yes	No	No	No

As nouns, biologist is a hypernym of physiologist; that is, biologist is a word with a broader meaning than physiologist:

Other hypernyms of physiologist include life scientist.

physiologist (noun)	biologist (noun)
a biologist specializing in physiology	(biology) a scientist who studies living organisms