protoplasm vs platelet

protoplasm and platelet both are nouns.

Word	Noun	Adjective	Verb	Adverb
protoplasm	Yes	No	No	No
platelet	Yes	No	No	No

As nouns, platelet is a hyponym of protoplasm; that is, platelet is a word with a more specific, narrower meaning than protoplasm:

protoplasm: the substance of a living cell (including cytoplasm and nucleus)
platelet: tiny bits of protoplasm found in vertebrate blood; essential for blood clotting

Other hyponyms of protoplasm include cytol, cytoplasm, karyoplasm, nucleoplasm, germ plasm, plasm, blood platelet, thrombocyte.

protoplasm (noun)	platelet (noun)
the substance of a living cell (including cytoplasm and nucleus)	tiny bits of protoplasm found in vertebrate blood; essential for blood clotting