sperm vs gamete

sperm and gamete both are nouns.

Word	Noun	Adjective	Verb	Adverb
sperm	Yes	No	No	No
gamete	Yes	No	No	No

As nouns, gamete is a hypernym of sperm; that is, gamete is a word with a broader meaning than sperm:

sperm: the male reproductive cell; the male gamete
gamete: a mature sexual reproductive cell having a single set of unpaired chromosomes

sperm (noun)	gamete (noun)
the male reproductive cell; the male gamete	a mature sexual reproductive cell having a single set of unpaired chromosomes