in vivo vs biological science

in vivo is not a noun while biological science is a noun.

Word	Noun	Adjective	Verb	Adverb
in vivo	No	Yes	No	Yes
biological science	Yes	No	No	No

in vivo (noun)	biological science (noun)
	the science that studies living organisms

in vivo (adjective)	biological science (adjective)
of a biological process occurring within a living organism

in vivo (adverb)	biological science (adverb)
in the living organism