Biology Chapter 17 Organizing Life’s Diversity

17.1 Aristotle  Aristotle developed the first system of biological classification He divided all organisms into plants or animalsHe divided all organisms into plants or animals  He divided plants into shrubs, herbs, and trees  He divided animals into groups based on characteristics such as habitat and physical features

17.1 Linnaeus  Linnaeus developed a classification system in the late 1700’s that grouped organisms based on structural similarities We still use this system as the basis for modern classificationWe still use this system as the basis for modern classification Linnaeus developed the idea of binomial nomenclature-each organism is identified by 2 names, the genus and the specific epithetLinnaeus developed the idea of binomial nomenclature-each organism is identified by 2 names, the genus and the specific epithet This system also indicates the evolutionary relationships between organismsThis system also indicates the evolutionary relationships between organisms

17.1 Scientific Names  Latin is used for scientific naming of organisms This language is used because it does not change as a result of the fact that it is a “dead” languageThis language is used because it does not change as a result of the fact that it is a “dead” language  Scientific names are to be written in italics when typed and underlined when handwritten  The first letter of the genus is uppercase and the first letter of the specific epithet is lowercase

17.1 Uses of Taxonomy  Taxonomy is used to study relationships between living and extinct species  Taxonomy is used to easily identify unknown or unfamiliar organisms  Taxonomy can also be used to predict whether or not new species have economic value based on similar species

17.1 Taxonomy of Living Things  Organisms are classified first by broad characteristics, then are further divided by more and more specific characteristics until individual species are identified  In order from least specific to most specific, organisms are classified in the following pattern: domain, kingdom, phylum, class, order, family, genus, species  domain is a recent addition to taxonomy and may not yet be widely used or accepted

17.2 Evolutionary Relationships  Evolutionary Relationships are determined based on similarities in five characteristics: Structure-physical characteristicsStructure-physical characteristics Breeding behavior- methods to attract a mate- sounds, dances, etc.Breeding behavior- methods to attract a mate- sounds, dances, etc. Geographical distribution-where in the world they live, including climate and physical locationGeographical distribution-where in the world they live, including climate and physical location Chromosomes- numbers and structures of chromosomesChromosomes- numbers and structures of chromosomes Biochemistry- DNA sequences and protein chainsBiochemistry- DNA sequences and protein chains

17.2 Phylogeny  Phylogeny is the evolutionary history of a species Phylogenic classification is a way of classifying organisms that shows the evolutionary relationships between themPhylogenic classification is a way of classifying organisms that shows the evolutionary relationships between them Two types of phylogenic diagrams:Two types of phylogenic diagrams:  Cladogram  Fan model

17.2 Cladistics  Cladistics assumes that as organisms evolve from a common ancestor, they maintain some derived traits Cladistics uses cladograms, or branching diagrams that show relationships among organismsCladistics uses cladograms, or branching diagrams that show relationships among organisms  Each branch shows a different organism  The closer together 2 branches are, the closer the relationship between the organisms  Changes in traits may be written under the branches  They do not show direct ancestry, only likely evolutionary patterns  An example is on p. 452

Section 17.2 Summary – pages Cladistics Theropods Allosaurus Sinornis Velociraptor Archaeopteryx Robin Light bones 3-toed foot; wishbone Down feathers Feathers with shaft, veins, and barbs Flight feathers; arms as long as legs

17.2 Fan Models  Fan models can be used to show either relative numbers of organisms in a group, or be set up as a timeline that shows the time of extinction of organisms (or both) Organisms in the same ray (section of the fan) share more characteristicsOrganisms in the same ray (section of the fan) share more characteristics They can be used to show connections between extinct and current speciesThey can be used to show connections between extinct and current species An example is on pp An example is on pp

Section 17.2 Summary – pages Life’s Six Kingdoms Life’s Six Kingdoms

17.2 Six Kingdoms  There are 6 kingdoms of organisms, classified by differences in methods for obtaining energy and cellular structures ArchaebacteriaArchaebacteria EubacteriaEubacteria ProtistsProtists FungiFungi PlantsPlants AnimalsAnimals

17.2 Archaebacteria  Archaebacteria are types of prokaryotes that: Are UnicellularAre Unicellular Lack a membrane bound nucleusLack a membrane bound nucleus Are Autotrophic (photosynthetic and chemosynthetic) and heterotrophicAre Autotrophic (photosynthetic and chemosynthetic) and heterotrophic Includes several hundred speciesIncludes several hundred species Generally live in oxygen-free, extreme environmentsGenerally live in oxygen-free, extreme environments Have genes that are similar in structure to eukaryotesHave genes that are similar in structure to eukaryotes

17.2 Eubacteria  Eubacteria are types of prokaryotes that: Are UnicellularAre Unicellular Lack a membrane bound nucleusLack a membrane bound nucleus Are Autotrophic (photosynthetic and chemosynthetic) and heterotrophicAre Autotrophic (photosynthetic and chemosynthetic) and heterotrophic Includes 5000 speciesIncludes 5000 species Have very strong cell wallsHave very strong cell walls Are sometimes helpful or harmful, but generally harmlessAre sometimes helpful or harmful, but generally harmless Live in most habitats, but not extremesLive in most habitats, but not extremes

17.2 Protists  Protists are types of eukaryotes that: Lack complex organ systemsLack complex organ systems Live in moist environmentsLive in moist environments Have been around for up to 2 billion yearsHave been around for up to 2 billion years Can be unicellular or multi-cellularCan be unicellular or multi-cellular Can be plant-like, animal-like or fungus- likeCan be plant-like, animal-like or fungus- like

17.2 Fungi  Fungi are eukaryotes who: Are heterotrophsAre heterotrophs Do not move from place to placeDo not move from place to place Can be unicellular or multi-cellularCan be unicellular or multi-cellular Absorb nutrients from organic materials in the environmentAbsorb nutrients from organic materials in the environment Have been around for over 400 million yearsHave been around for over 400 million years Have more than 50,000 different speciesHave more than 50,000 different species

17.2 Plants  Plants are photosynthetic eukaryotes who: Are multi-cellularAre multi-cellular Do not move from place to placeDo not move from place to place Usually contain chloroplasts and have cell walls made of celluloseUsually contain chloroplasts and have cell walls made of cellulose Have cells organized into tissues, then organs, then organ systemsHave cells organized into tissues, then organs, then organ systems Are over 400 million years oldAre over 400 million years old  Scientists believe they are much older since plants do not fossilize well Have over 250,000 known speciesHave over 250,000 known species

17.2 Animals  Animals are eukaryotes who: Are multi-cellularAre multi-cellular Are heterotrophsAre heterotrophs Can move from place to placeCan move from place to place Have cells without cell wallsHave cells without cell walls Have cells organized into tissues, then organs, then organ systemsHave cells organized into tissues, then organs, then organ systems Have existed for about 600 million yearsHave existed for about 600 million years