16.1 Early Classification
| Taxonomy - field of biology that deals with classifying organisms. |
| Scientists use an international system classifying and naming all organisms. |
| Taxon - a category in which all related organisms are placed. |
| Linneaus based his system on structural similarities between organisms. |
| Hierarchy - a ranking system. |
| Categories were ranked from the broadest and general to smallest and specific. |
| Linneaus divided all organisms into two groups, plants and animals. |
16.2 Modern Classification
| Two additional classifications levels were added to the original five created by Linneaus. |
| Plant kingdom is divided into categories called divisions. |
| Binomial nomenclature - identifying organisms by their genus and species names. |
| Species is like a person's first name. |
| Genus is like a person's last name. |
| The "first name" or species name, is placed last, as in many Asian. |
| Kingdoms group organisms in fundamental characteristics. |
| They are major cell structure, method of obtaining nutrients and metabolism. |
| Monera - cells of prokaryotes do not have a nuclear membrane or any membrane organelles. |
| Protista - includes unicellular and a few similar multicellular eukaryotes. |
| Plantlike protists are photosynthetic and commonly called algae. |
| Fungi - act as either decomposers or parasites in nature. |
| Fungi includes molds, mildews, mushrooms, yeasts and many relatives. |
| Kingdom Plantae includes mosses, ferns, cone-bearing plants and flowering plants. |
| Kingdom Animalia - animal cells have no cell walls. |
16.3 The Basis for Classification
| Organisms are classified by physical structure, biochemical analyses of DNA and protein. |
| The more differences between DNA sequences of two organisms, the more distant the common ancestor. |
| Newer evidence indicates crocodiles are actually more closely related to birds. |
16.4 Family Tree of Major Taxa
| The tips of the branches on the tree represent the most modern organisms to evolve in the group. |
| Each time a branch divides into a smaller branch, it shows the emergence of a new ancestral species. |
16.5 Dichotomous Key
| Dichotomous key, classification key, is a tool used for identifying unfamiliar organisms. |