1. Chapter 18 Classification The diversity of life

2. Why is it necessary to classify? 1.5 million species on the planet so all creatures must be organized with a universal system. We call this taxonomy. Scientists cannot use common names because they change depending on where you live. For example: cougar, panther, puma, mountain lion all represent the same animal. It has a scientific name – Felis concolor

3. Scientific Names Carolus Linneaus – Swedish botanist who began the modern naming system. Developed a two word naming system called binomial nomenclature (latin) 2 name naming system Scientific names are Descriptive In Latin 2 words – capitalize the first letter of the first word and lowercase everything else. First word is Genus second word is species Ursus maritimus

4. Examples scientific name = genus + species Homo sapien Canis familiarius Felis domesticus Drosophilia melanogaster Human Dog Cat Fruit fly

5. Classification System We organize all life on Earth into 9 levels. Each level is called a taxon. Domain is the largest – 3 large groups (see below) Species is the smallest

6. Classification Levels Example: Grizzly bear

7. Human Taxonomy Levels

8. Changing Number of Kingdoms History of Kingdoms: 1700’s - 2 kingdoms –Plants and Animals 1800’s – 3 kingdoms – Plants, Animals, Protists (pond water critters) 1950’s – 5 kingdoms – Monera (bacteria), Protists, Fungi, Plants and Animals 1990’s – 6 kingdoms - Eubacteria, Archaebacteria, Protists, Fungi, Plants and Animals.

9. Section 18-3 Kingdoms and Domains Shown below are the three domains and the 6 modern kingdoms we use today.

10. Domain: Bacteria and Archaea 1. Kingdom: Bacteria unicellular prokaryotic cell wall contains a special molecule called peptidoglycan. 2. Kingdom: Archaebacteria Live in extreme environments Cell wall lacks peptidoglycan

11. Domain Eukarya 3. Kingdom Protista Eukaryotic organisms (most are one celled) Shows the greatest variety of organisms Photosynthetic or heterotrophic

12. Domain Eukarya 4. Kingdom Fungi Absorptive heterotrophs – absorb nutrients through their bodies Feed on dead or decaying organic matter Many are multicellular Yeast is unicellular

13. Domain Eukarya 5. Kingdom Plantae Multicellular Autotrophs (do photosynthesis) Cellulose in cell wall

14. Domain Eukarya 6. Kingdom Animalia Multicellular Heterotrophic Eukaryotic Invertebrates and Vertebrates