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Download Kingdoms and Domains College Biology Mr. Lee Room 320
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Kingdoms and Domains Biology Facilitator: Mr. Lee Room 320 Objectives Name the six kingdoms Describe the three-domain system of classification Identify the purpose of Cladograms Modern Evolutionary Classification In Linnaeus’s time the only known differences between living things were the fundamental traits that separated plants from animals Biologists now know that the two kingdoms do not adequately represent the life on Earth Three-Domain System The domain is a more inclusive category, larger than a kingdom The three domains: Eukarya Bacteria Archaea Domain Eukarya Consist of all organisms that have a nucleus Kingdom Protista: Composed of eukaryotic organisms that can’t be classified as animals, plants, or fungi Can be unicellular or multicellular Some are photosynthetic and some are heterotrophic Domain Eukarya Kingdom Fungi: Are heterotrophs They secret digestive enzymes into their food source Most are multicellular but some can be unicellular Cell walls contain chitin Domain Eukarya… Kingdom Plantae: Are multicellular Are photosynthetic autotrophs Have cell walls made of cellulose Kingdom Animalia: Are multicellular Are heterotrophs Domain Bacteria Kingdom Eubacteria Are unicellular Are prokaryotic Have rigid cell walls made of peptidoglycan Domain Archaea Kingdom Archaebacteria Are unicellular Are prokaryotic Live in extreme environments Hot springs Brine pools Many do not need oxygen Their cell walls lack peptidoglycan Evolutionary Classification Phylogeny is the study of evolutionary relationships among organisms Biologist now group organisms into categories that represent lines of evolutionary descent, not just physical similarities This strategy is called evolutionary classification All members of a genus have a common ancestor The higher the level of taxon, the further back in time is the common ancestor Classification Using Cladograms Cladistic analysis indentifies and conceders only characteristics that are evolutionary innovations Derived characters are characteristics that appear in recent parts of a lineage but not in its older members Classification Using Cladograms… Cladograms are diagrams that use derived characters to show evolutionary relationships Cladograms are like an evolutionary tree Molecular Clocks Molecular clocks use DNA comparisons to estimate the length of time that two species have been evolving independently The degree of change in the sequence of DNA indicates how long ago the two species shared a common ancestor Mutations that have no effect on phenotype accumulate at a steady rate By comparing these mutations it can be determined how the two species shared a common ancestor Molecular Clocks… Similarities in DNA can be used to help determine classification and evolutionary relationships DNA evidence can be used to show relationships between species and how species have changed The more similar the DNA is from one organism to another the closer they share a common ancestor Review Name the six kingdoms: Describe the threedomain system of classification: Eubacteria Archaebacteria Protista Fungi Plantae Animalia The domain is a more inclusive category, larger than a kingdom The three domains: Eukarya Bacteria Archaea Review… Identify the purpose of Cladograms: Cladograms are diagrams that use derived characters to show evolutionary relationships Learn Long Live Long
