- Extremely diverse: can be algae-like, animal-like, fungus-like; unicellular, multicellular
- Evolutionary relationships are weak, poorly understood, or both
- Features shared by two or more groups may represent convergent evolution
Algae-Like
- All obtain energy by photosynthesis, have chlorophyll a
Protozoa/Animal like
- Heterotrophs: Consume living cells or dead organic matter
Fungus-Like
- Resemble fungus bcuz they form filaments or spore-bearing bodies