face up vs take on

face up and take on both are verbs.

Word	Noun	Adjective	Verb	Adverb
face up	No	No	Yes	No
take on	No	No	Yes	No

As verbs, take on is a hyponym of face up; that is, take on is a word with a more specific, narrower meaning than face up:

Other hyponyms of face up include tackle, undertake.

face up (verb)	take on (verb)
deal with (something unpleasant) head on	take on a certain form, attribute, or aspect
	contend against an opponent in a sport, game, or battle
	admit into a group or community
	accept as a challenge
	take on titles, offices, duties, responsibilities