1. Chapter 18: Classification

2. You are required to put on clothes each day before coming to school. How do you go about this in the most efficient manner to get you out of the house on time for school each day? There are 1.5 million different identified species (alive and extinct) How can we keep all these organisms in order?

3. Classification –is the method of logically grouping organisms based on some common characteristics Taxonomy –does the actually grouping into the groups called TAXON (s – TAXA) with some kind of biological significance. –Ie. Things that fly, swim, walk, have feathers, etc.

4. How many different terms can you think of for trying to tell someone something is really good? Do these terms have meanings that may confuse someone else? There is a need for a common term to describe an individual organism so that all people understand when the term is used. Carolus Linnaeus (mid 1700’s) came up with the system of Binomial Nomenclature.

5. Carolus Linnaeus He assigned two Latin names to each different species of organisms. This is their Scientific name. Homo sapiens (human) Homo sapiens Ursus maritimus (polar bear) Ursus maritimus Acer rubrum (red maple) Ursus arctos (grizzly bear)

6. Cur Latin? Scientific names will always be in Latin. Latin is a dead language that will not evolve unlike other languages. Little chance of change through time. Universally understood in the science community

7. The Taxonomic order: From the largest, most inclusive group to the smallest, most exclusive, specific taxa. Taxa Human Grizzly Chimp Kingdom Animalia AnimaliaAnimalia Phylum Chordata ChordataChordata Class Mammalia Mammalia Mammalia Order Primate CarnivoraPrimate Family Hominoidae UrsidaeHominoidae Genus Homo UrsusPan Species sapiens arctostroglodyte Which two organisms are more closely related and why?

8. Modern methods of classification rely on evolutionary relationships in place of homologous structures. Birds, bats and insects should not be classified together because they all have wings and fly.

9. Evolutionary classification classifies organisms in taxa based on lines of common descent, not physical similarities –Uses proteins, DNA and genes to determine classification and relatedness Human Genome project that decoded our DNA helped to show evolutionary relationships with other species, even totally unrelated species. Think back to your Amino Acid lab –The more closely related organisms are, the more Amino acids they will have in common and the more recently they evolved from some kind of common ancestry.

10. Kingdoms and Domains 1700’s – Plants and Animals only 1800’s – Protists, Plants and Animals 1950’s – 5 Kingdom system, including Fungus and Monera Now – 6 Kingdoms divided into 3 Domains

11. Domains: 1.Bacteria 1.Bacteria – Unicellular, prokaryotic (no nuclear membrane) with cell walls made up of peptidoglycan. –Kingdoms: Eubacteria –Kingdoms: Eubacteria – true bacteria. “Normal “ bacteria 2.Archaea 2.Archaea – Unicellular, prokaryotic but do not have cell walls containing peptidoglycan. These are primitive organisms that could withstand very harsh environments and a lack of oxygen. –Kingdom: Archaebacteria –Kingdom: Archaebacteria – methanogens in the digestive tract of animals and halophiles that live in the Dead Sea.

12. Eukarya 3.Eukarya – Eukaryotic organisms. May be uni or multi cellular. All have nuclear membranes –Kingdom: Protista –Kingdom: Protista – basically unicellular. Have plant-like, animal – like or fungus- like representatives. ***Most difficult kingdom to classify. No clear cut boundaries. Ie.Amoeba, paramecium, slime mold, Volvox –Kingdom Fungi –Kingdom Fungi – Absorptive heterotrophs, basically multicellular organisms with cell walls made up of chitin. Ie. Yeast, mushroom, molds –Kingdom Plantae –Kingdom Plantae – Multicellular, photosynthetic organisms. All are autotrophic. Nonmotile with cell walls containing cellulose. Ie. Mosses, ferns, conifers, flowering plants and some algae. –Kingdom Animalia –Kingdom Animalia – Multicellular, ingestive heterotrophs. All lack cell walls. Motile for some time in their life cycle. Ie. Sponges, jelly fish, worms, insects, octopus, fish, birds, reptiles, you

13. The New and Improved Six Kingdom System KingdomCell Type# of CellsNutrition Representative organism Archaebacteria ProkaryoticUnicellular Autotrophic or Heterotrophic Blue-green bacteria, Methanogens Eubacteria ProkaryoticUnicellular Autotrophic or Heterotrophic E.coli, Staphylococcus, Streptococcus, Spirochetes Protista Eukaryotic Uni, multi or colonial Autotrophic or Heterotrophic Amoeba, Paramecium, Euglena, Plasmodium, Diatoms Fungi Eukaryotic Uni or Multicellular Absorptive Heterotroph Yeast, Mushrooms, Molds, smuts, rusts Plantae EukaryoticMulticellular Autotrophic (some heterotrophic) Mosses, ferns, Horsetails, Conifers, Flowering plants Animalia EukaryoticMulticellular Ingestive Heterotroph Sponges, Coral, Sea stars, EW, Insects, Fish, Amphibians, Reptiles, Birds, Mammals