molecular biology vs biology

molecular biology and biology both are nouns.

Word	Noun	Adjective	Verb	Adverb
molecular biology	Yes	No	No	No
biology	Yes	No	No	No

As nouns, biology is a hypernym of molecular biology; that is, biology is a word with a broader meaning than molecular biology:

molecular biology: the branch of biology that studies the structure and activity of macromolecules essential to life (and especially with their genetic role)
biology: the science that studies living organisms

Other hypernyms of molecular biology include biological science.

molecular biology (noun)	biology (noun)
the branch of biology that studies the structure and activity of macromolecules essential to life (and especially with their genetic role)	the science that studies living organisms
	all the plant and animal life of a particular region
	characteristic life processes and phenomena of living organisms