The five kingdoms
Animal, Plant, Fungus, Prokaryote, Protoctist — distinguished by cell features and nutrition.
Animals.
- Multicellular EUKARYOTES (cells with nuclei).
- Cells have NO cell walls — flexible.
- HETEROTROPHIC: feed by eating other organisms.
- Often capable of complex movement.
- Examples: insects, fish, mammals, worms, jellyfish.
Plants.
- Multicellular EUKARYOTES.
- Cells have CELLULOSE cell walls (rigid).
- Cells contain CHLOROPLASTS for photosynthesis.
- AUTOTROPHIC: make own food via photosynthesis.
- Often have roots, stems, leaves.
- Examples: oak trees, grass, ferns, mosses.
Fungi.
- USUALLY multicellular (yeasts are single-celled).
- Cells have walls of CHITIN (different from plants' cellulose).
- Body usually a network of thread-like HYPHAE forming a mycelium.
- SAPROTROPHIC: secrete enzymes onto dead matter and absorb nutrients (or PARASITIC).
- Examples: mushrooms, yeast, mould, athlete's foot fungus.
Prokaryotes (Bacteria).
- SINGLE-CELLED.
- NO NUCLEUS — DNA loose in cytoplasm.
- Cells have walls (peptidoglycan).
- Variable nutrition: many heterotrophic, some photosynthetic.
- Examples: E. coli, Bacillus, blue-green algae (cyanobacteria).
Protoctists.
- Eukaryotic but usually SINGLE-CELLED, or simple multicellular (e.g. seaweed).
- 'Catch-all' kingdom for eukaryotes that don't fit animal/plant/fungus.
- Variable nutrition.
- Examples: Amoeba, Paramecium, Plasmodium (malaria parasite), Euglena, algae.
Cambridge tip. Distinguishing features asked include: cell type (eukaryotic vs prokaryotic), cell walls (yes/no, what material), unicellular vs multicellular, nutrition type. Nail TWO features per kingdom.
- Animal: multicellular, no walls, heterotrophic.
- Plant: cellulose walls, chloroplasts, autotrophic.
- Fungus: chitin walls, saprotrophic.
- Prokaryote: NO nucleus, peptidoglycan walls.
- Protoctist: simple eukaryotes; variable nutrition.