fission vs asexual reproduction

fission and asexual reproduction both are nouns.

Word	Noun	Adjective	Verb	Adverb
fission	Yes	No	No	No
asexual reproduction	Yes	No	No	No

As nouns, asexual reproduction is a hypernym of fission; that is, asexual reproduction is a word with a broader meaning than fission:

fission: reproduction of some unicellular organisms by division of the cell into two more or less equal parts
asexual reproduction: reproduction without the fusion of gametes

Other hypernyms of fission include agamogenesis.

fission (noun)	asexual reproduction (noun)
a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy	reproduction without the fusion of gametes
reproduction of some unicellular organisms by division of the cell into two more or less equal parts