life science vs natural science

life science and natural science both are nouns.

Word	Noun	Adjective	Verb	Adverb
life science	Yes	No	No	No
natural science	Yes	No	No	No

As nouns, natural science is a hypernym of life science; that is, natural science is a word with a broader meaning than life science:

life science: any of the branches of natural science dealing with the structure and behavior of living organisms
natural science: the sciences involved in the study of the physical world and its phenomena

life science (noun)	natural science (noun)
any of the branches of natural science dealing with the structure and behavior of living organisms	the sciences involved in the study of the physical world and its phenomena