Biology · BIOLOGICAL CLASSIFICATION

Why were acellular organisms like viruses, viroids, and prions not assigned a place in R.H. Whittaker's Five Kingdom Classification?

1. Because Whittaker included only aquatic eukaryotic organisms in his classification scheme
2. Because they carry double-stranded peptidoglycan walls not recognized in Whittaker's key
3. Because they are non-cellular/acellular entities with an inert crystalline structure outside living cells, not considered truly 'living'
4. Because they synthesize their own food via chemosynthesis without cell organelles