pubescent vs biological science

pubescent is not a noun while biological science is a noun.

Word	Noun	Adjective	Verb	Adverb
pubescent	No	Yes	No	No
biological science	Yes	No	No	No

pubescent (noun)	biological science (noun)
	the science that studies living organisms

pubescent (adjective)	biological science (adjective)
covered with fine soft hairs or down
(of animals especially human beings) having arrived at the onset of puberty (the age at which sex glands become functional) but not yet fully mature