gamete vs sex cell

gamete and sex cell both are nouns.

Word	Noun	Adjective	Verb	Adverb
gamete	Yes	No	No	No
sex cell	Yes	No	No	No

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

gamete: a mature sexual reproductive cell having a single set of unpaired chromosomes
sex cell: a spermatozoon or an ovum; a cell responsible for transmitting DNA to the next generation

Other hypernyms of gamete include germ cell, reproductive cell.

gamete (noun)	sex cell (noun)
a mature sexual reproductive cell having a single set of unpaired chromosomes	a spermatozoon or an ovum; a cell responsible for transmitting DNA to the next generation