gestation vs biological time

gestation and biological time both are nouns.

Word	Noun	Adjective	Verb	Adverb
gestation	Yes	No	No	No
biological time	Yes	No	No	No

As nouns, biological time is a hypernym of gestation; that is, biological time is a word with a broader meaning than gestation:

gestation: the period during which an embryo develops (about 266 days in humans)
biological time: the time of various biological processes

gestation (noun)	biological time (noun)
the conception and development of an idea or plan	the time of various biological processes
the state of being pregnant; the period from conception to birth when a woman carries a developing fetus in her uterus
the period during which an embryo develops (about 266 days in humans)