Protoplastid is a derived term of plastid.

In biology|lang=en terms the difference between protoplastid and plastid

is that protoplastid is (biology) an immature plastid that is incapable of photosynthesis while plastid is (biology) any of various organelles found in the cells of plants and algae, often concerned with photosynthesis.

As nouns the difference between protoplastid and plastid

is that protoplastid is (biology) an immature plastid that is incapable of photosynthesis while plastid is (biology) any of various organelles found in the cells of plants and algae, often concerned with photosynthesis.