diversity of life: introduction to biological classification by deanne erdmann, ms bioed online
TRANSCRIPT
Diversity of Life:
Introduction to Biological
Classification
By Deanne Erdmann, MS
BioEd Online
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Why Do We Classify Organisms?
Biologists group organisms to represent similarities and proposed relationships.
Classification systems change with expanding knowledge about new and well-known organisms.
Tacitus bellus
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History of the Kingdom System
http://earthlingnature.wordpress.com/2011/12/05/a-brief-history-of-the-kingdoms-of-life/
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Leucaena leucocephala Lead tree
Classification
Binomial Nomenclature Two part name (Genus, species)
Hierarchical Classification Seven Taxonomic Categories
Systematics Study of the evolution of biological
diversity
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Carolus von Linnaeus(1707-1778)
Swedish scientist who laid the foundation for
modern taxonomy
Binomial Nomenclature
Carolus von Linnaeus
Two-word naming system Genus
Noun, Capitalized, Underlined or Italicized
Species Descriptive, Lower Case,
Underlined or Italicized
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Hierarchical Classification
Taxonomic categories Kingdom King Phylum Philip Class Came Order Over Family For Genus Good Species Soup
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Kingdoms and Domains
Bacteria Archaea Eukarya
Bacteria Archaea Protista Plantae Fungi Animalia
Monera Protista Plantae Fungi Animalia
The three-domain system
The six-kingdom system
The traditional five-kingdom system
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Systematics:Evolutionary Classification of Organisms
Systematics is the study of the evolution of biological diversity, and combines data from the following areas.
Fossil record Comparative homologies Cladistics Comparative sequencing of DNA/RNA among
organisms Molecular clocks
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Taxonomic Diagrams
Mammals Turtles Lizards and Snakes
Crocodiles Birds Mammals Turtles Lizards and Snakes
Crocodiles Birds
CladogramPhylogeneticTree
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www.BioEdOnline.orghttp://evolution.berkeley.edu/evolibrary/article/phylogenetics_02
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Dichotomous Keys Identify Organisms
Dichotomous keys versus evolutionary classification
Dichotomous keys contain pairs of contrasting descriptions.
After each description, the key directs the user to another pair of descriptions or identifies the organism.
Example: 1. a) Is the leaf simple? Go to 2
b) Is the leaf compound? Go to 3
2. a) Are margins of the leaf jagged? Go to 4b) Are margins of the leaf smooth? Go to 5
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Dichotomous key
http://www.classzone.com/cz/books/bio_09/resources/htmls/animated_biology/unit7/bio_ch21_0657_ab_tree.html
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Plant Phyla
bryophyta
Filicinophyta
Coniferophyta
Angiospermophyta
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Bryophyta (“bryo-”: moss)
mosses, liverworts and hornworts
stems radial symmetry (mosses)
stems bilateral symmetry (liverworts), no lignin
no true leaves or roots
no cuticle.
reproductive structure are called sporangium which are on long stalks with capsules on end. In this image the spore is released from the sporangium to develop into another plant.
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Filicinophyta (ferns)
leaves
roots non woody stems
divided leaves
height up to 20 m
reproduction: sporangia (sori) contain reproductive spores
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Coniferophytes (conifers and pines)
trees (100m), shrubs,
woody (lignin) stems,
waxy narrow needle like leaves.
vascular system (tracheids)
reproduction: monoecious, microsporophylls (male) non motile gametes often with air bladders for water/ air dispersal. macrosporophylls (female) ovule on cone scale
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Angiospermophyta (flowering plants and grasses)
roots
stems
leaves.
vascular bundles (xylem/ phloem )
waxy cuticle,
annual or perennial up to 100m
reproduction:
ovules in an enclosed carpel structure.
pollen grains produced from anthers
variety of pollen transfers vectors
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Animal Phyla (just the invertebrates for now…)
Porifera (sponges)
Cnidaria (jellyfish…)
Platyhelminthes (flatworms)
Annelida (segmented worms)
Mollusca (snails, clams, octopus…)
Arthropoda (insects, crustaceans, spiders...)
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