Undiferentiated or Undifferentiated: How To spell?
The word Undiferentiated is misspelled against Undifferentiated, an adjective meaning "Not differentiated; specifically (Biol.), homogenous, or nearly so; -- said especially of young or embryonic tissues which have not yet undergone differentiation (see Differentiation, 3), that is, which show no visible separation into their different structural parts."
Undifferentiated has double "ff" is mispronounced as "f"Remember double 'FF' in between the strings Undi & erentiated which should not be misspelled with single 'F'
Wrong Spelling:  Undi-f-erentiated  Correct Spelling:  Undi-ff-erentiated 
Find more wrongly spelled words of Undifferentiated to spell it well.