Correct answer : are eukaryotes
1. They are not plants. Plants belong their own respective kingdom : Plantae, while Mushrooms are in the fungi kingdoms.
2. As the statement states, they are heterotrophic. They do not have the ability to use photosynthesis, as they take nutrients from their surrounding environment.
3. Eukaryotes = Multiple cells. Yes, they are eukaryotes.
4. Prokaryotes are almost always bacteria.
5. Unicellular = one cell
