biology vs physiology

biology and physiology both are nouns.

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

As nouns, physiology is a hyponym of biology; that is, physiology is a word with a more specific, narrower meaning than biology:

biology: the science that studies living organisms
physiology: the branch of the biological sciences dealing with the functioning of organisms

biology (noun)	physiology (noun)
the science that studies living organisms	processes and functions of an organism
all the plant and animal life of a particular region	the branch of the biological sciences dealing with the functioning of organisms
characteristic life processes and phenomena of living organisms