microgametophyte vs gametophyte

microgametophyte and gametophyte both are nouns.

Word	Noun	Adjective	Verb	Adverb
microgametophyte	Yes	No	No	No
gametophyte	Yes	No	No	No

As nouns, gametophyte is a hypernym of microgametophyte; that is, gametophyte is a word with a broader meaning than microgametophyte:

microgametophyte: the male gametophyte produced by a microspore
gametophyte: the gamete-bearing individual or phase in the life cycle of a plant having alternation of generations

microgametophyte (noun)	gametophyte (noun)
the male gametophyte produced by a microspore	the gamete-bearing individual or phase in the life cycle of a plant having alternation of generations