ameba vs rhizopod

ameba and rhizopod both are nouns.

Word	Noun	Adjective	Verb	Adverb
ameba	Yes	No	No	No
rhizopod	Yes	No	No	No

As nouns, rhizopod is a hypernym of ameba; that is, rhizopod is a word with a broader meaning than ameba:

ameba: naked freshwater or marine or parasitic protozoa that form temporary pseudopods for feeding and locomotion
rhizopod: protozoa characterized by a pseudopod

Other hypernyms of ameba include rhizopodan.

ameba (noun)	rhizopod (noun)
naked freshwater or marine or parasitic protozoa that form temporary pseudopods for feeding and locomotion	protozoa characterized by a pseudopod