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Chapter 18. Classification. What is Classification?. Classification is the grouping of objects based on similarities Classifying Biology and Chemistry as Science is a type of classification We classify organisms to help name them and to create order
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Chapter 18 Classification
What is Classification? • Classification is the grouping of objects based on similarities • Classifying Biology and Chemistry as Science is a type of classification • We classify organisms to help name them and to create order • Taxonomy is the branch of biology that groups and names organisms
How did taxonomy begin? • What do you call this animal? • Mountain lion, cougar, puma, panther
What is Classification? • Binomial nomenclature gives each species a two-part scientific name • The first word is the genus, the second is the species • Grizzly bear: Ursusarctos • Polar bear: Ursusmaritimus • Giant panda: Alluropodamelanoleuca • Most are Latin • Developed by Carolus Linnaeus in late 1700s
What is Classification? • Linnaeus’s classification included a hierarchal system with 7 levels • Taxon: grouping (categories) of organisms, plural is taxa • Kingdom: taxon of similar phyla • Phylum: taxon of similar classes • Class: taxon of similar orders • Order: taxon of similar families • Family: taxon of similar genera; example cat family is Felidae • Genus: taxon of similar species • Species: specifies organism; Homo sapiens
Classification • How do we determine how to group organisms together? • What similarities/differences are most important? • How do you classify a dolphin? Is it more similar to a fish or a cat? • Darwin’s ideas of evolution led to the study of phylogeny (evolutionary relationships among organisms)
Classificantion • Grouping organisms based on their evolutionary history is called evolutionary classification • Species with the same genus are more closely related than another genus • Same genus all share a common ancestor • The farther you go up in taxa, the further back the common ancestor was • Cladograms show relationships of evolutionary classification
Cladograms • https://www.youtube.com/watch?v=ouZ9zEkxGWg
Dichotomous Key • A dichotomous key is multiple sets of paired statements used to identify organisms • http://nationalzoo.si.edu/Education/ConservationCentral/walk/walk4.html
3 Domains • Bacteria, Archaea, and Eukarya • Bacteria and Archaea are prokaryotes. • Domain Bacteria has Kingdom Eubacteria. “normal” bacteria • Domain Archaea has Kingdom Archebacteria. “weird” bacteria
Eukarya • Kingdom Protista • Most are unicellular • Live in moist environments • Diverse in ways they obtain nutrition. Ex. amoeba http://www.cellsalive.com/parasit.htm • Kingdom Fungi • Heterotrophic decomposers • Cell walls of chitin, ex. mushroom; pictures
Eukarya • Kingdom Plantae • Autotrophic, multicellular, have tissues • Cell walls of cellulose • Vascular plants – have vessels that transport water and sugars (ferns, conifers, flowering plants) • Xylem– tissue that moves water • Phloem – tissue that moves sugars • Nonvascular plants do not have these vessels., ex. mosses • Kingdom Animalia – multicellular heterotrophs. Do NOT have cell walls
Domain, Kingdom, Phylum… • Did Domain • King Kingdom • Philip Phylum • Cross Class • Over Order • For Family • Good Genus • Soup Species