For a Grade 9 text book: "Many more objects exist in the solar system besides the eight major planets. These are smaller and include moons, comets, protoplanets, such as Pluto, and tiny grains of dust and ice." Is this acceptably-worded or is it misleading? My take is that the term "protoplanet" refers to planetesimals that are part of a young still-forming system and have the potential to grow into planets. "Dwarf planets" are pretty much all they're ever going to be.