take on vs take up

take on

verb
  • To acquire, bring in, or introduce. 

  • To assume or take responsibility for. 

  • To (attempt to) dribble round (an opposition player). 

  • To catch on, do well; to become popular. 

  • To obtain the services of (a person) in exchange for remuneration; to give someone a job. 

  • To begin to have or exhibit. 

  • To attempt to fight, compete with, or engage with. 

  • To grieve or be concerned (about something or someone). 

take up

verb
  • To accept (a proposal, offer, request, etc.) from. 

  • To implement, to employ, to put into use. 

  • To review the solutions to a test or other assessment with a class. 

  • To begin doing (an activity) on a regular basis. 

  • To occupy; to consume (space or time). 

  • Synonym of take in (“tighten a belaying rope”) 

  • To resume. 

  • To pick up. 

  • To address (an issue). 

  • To shorten by hemming. 

How often have the words take on and take up occurred in a corpus of books? (source: Google Ngram Viewer )