Five Kingdoms vs Sub-cellular Agents — Comparison Table — Notes

Feature	Monera	Protista	Fungi	Plantae	Animalia
Cell type	Prokaryotic	Eukaryotic	Eukaryotic	Eukaryotic	Eukaryotic
Cell wall	Peptidoglycan (eubacteria) / Non-peptidoglycan (archaea) / Absent (Mycoplasma)	Silica (diatoms), Cellulose (dinoflagellates), Absent (protozoans)	Chitin	Cellulose	Absent
Body organisation	Unicellular	Mostly unicellular	Multicellular (except yeast)	Multicellular	Multicellular
Mode of nutrition	Auto/Hetero/Mixotrophic	Auto/Hetero/Mixotrophic	Heterotrophic $\frac{saprophytic}{parasitic}$	Autotrophic (photosynthetic)	Heterotrophic (holozoic)
Energy storage	Glycogen/starch	Varies	Glycogen (not starch)	Starch	Glycogen
Reproduction	Binary fission, budding	Asexual/Sexual	Spores (asexual+sexual)	Alternation of generations	Mostly sexual
Examples	E. coli, Nostoc, Mycoplasma	Euglena, Amoeba, Diatoms	Mucor, Agaricus, Saccharomyces	Fern, Rose, Pine	Hydra, Frog, Human

Feature	Virus	Viroid	Prion
Nucleic acid	DNA OR RNA (never both)	RNA only (naked, circular)	None
Protein coat (capsid)	Present	Absent	Protein only (misfolded)
Size	20–300 nm	Smaller than viruses	Smaller than viruses
Discovery	Pasteur (rabies); Ivanowsky (TMV, 1892)	T.O. Diener (1971)	Stanley Prusiner (1982)
Nature	Non-cellular obligate parasite	Infectious RNA	Infectious protein
Host	Animals, plants, bacteria	Plants only	Animals only
Disease examples	TMV, HIV, Bacteriophage	Potato spindle tuber disease	Mad cow disease (BSE), CJD

Feature	Archaebacteria	Eubacteria
Cell wall	Lacks peptidoglycan	Has peptidoglycan
Habitat	Extreme (hot springs, salt lakes, marshes)	Diverse — soil, water, host organisms
Gram staining	Does not apply	Gram +ve or Gram -ve
Examples	Methanobacterium, Halobacterium	E. coli, Nostoc, Mycoplasma
Significance	Methane production, bioremediation potential	Nitrogen fixation, disease, fermentation