The document describes the three-domain system of classifying life. It divides life into Archaea, Eubacteria, and Eukarya. Archaea and Eubacteria are prokaryotes without nuclei or organelles, while Eukarya are more complex eukaryotic organisms with nuclei and organelles. Eukarya are further divided into four kingdoms - Protista, Fungi, Plantae, and Animalia. Protista include unicellular organisms like protozoa and algae. Fungi are multicellular decomposers with cell walls made of chitin. Plantae are multicellular and autotrophic organisms that perform photosynthesis. Animalia are

1. Figure 10.1
The Three-Domain System

3. • Broadest, most inclusive taxon
• Three domains
• Archaea and Eubacteria are unicellular
prokaryotes (no nucleus or membrane-
bound organelles)
• Eukarya are more complex and have a
nucleus and membrane-bound organelles
Domains

4. ARCHAEA
• Prokaryotes (NO NUCLEUS)
• Many live in HARSH environments
• Found in:
– Sewage Treatment Plants
– Thermal or Volcanic Vents
– Hot Springs or Geysers that are acid
– Very salty water (Dead Sea; Great Salt Lake)

5. 5
ARCHAEAN

7. EUBACTERIA
• Prokaryotes (NO NUCLEUS)
• Some may cause DISEASE
– Strep throat, pneumonia, ect.
• Found in ALL HABITATS
• Important decomposers for environment
• Commercially important in making cottage
cheese, yogurt, buttermilk, etc.

8. 8
Live in the intestines of animals

10. Domain Eukarya is Divided into
Four Kingdoms
• Protista (protozoans, algae…)
• Fungi (mushrooms, yeasts …)
• Plantae (multicellular plants)
• Animalia (multicellular animals)

11. Protista
•Most are unicellular
•Some are multicellular
•Some are autotrophic, while
others are heterotrophic
•Live in moist environments
•Lack complex organs

12. Kingdom Protista
• Ex: protozoa, algae, diatoms,

14. Fungi
• Multicellular, except yeast
• Absorptive heterotrophs (digest food outside
their body & then absorb it)
• Decomposers
• Cell walls made of chitin
• Do not move from place to place

15. Kingdom Fungi
• parasites or decomposers / molds, yeasts,
mushrooms…

16. Plantae
•ALL Multicellular
•Autotrophic
•Absorb sunlight to make
glucose – Photosynthesis
•Cell walls made of
cellulose

17. Kingdom Plantae
• seed plants, mosses, ferns

18. Animalia• Multicellular
• Ingestive heterotrophs (consume food and digest it
inside of their bodies)
• Move from place to place
• No cell wall
• Organ systems

19. Kingdom Animalia
• Reproduce
sexually
• There are fifteen
phyla of animals
• They range from
sponges to
chordates

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