Unit 11: Classification of Living Things

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Unit 11 Classification of Living Things
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Finding Order in Diversity

• To study the diversity of life, biologists use a
  classification system to name organisms and group
  them in a logical manner.
• Taxonomy is the branch of biology that groups and
  names organisms based on studies of their
  different characteristics.
• Biologists who study taxonomy are called
  taxonomists.
• Classification systems change with expanding
  knowledge.

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Carolus Linnaeus

• Swedish botanist
• Developed Binomial Nomenclature
• Two-word naming system
• Genus
• Noun, Capitalized, Underlined or Italicized
• Species
• Descriptive, Lower Case, Underlined or
  Italicized
• Each species is assigned a two-part scientific
  name
• Ex. Ursus arctos

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System of Classification

• Linnaeuss hierarchical system of classification
  includes eight levels (from largest to smallest)
• Grizzly Bear (common name)
• Domain Eukarya
• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Carnivora
• Family Ursidae
• Genus Ursus
• Species arctos

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System of Classification
D K P C O F G S

• Taxonomic categories, an acronym
• Domain Dear
• Kingdom King
• Phylum Phillip
• Class Came
• Order Over
• Family For
• Genus Good
• Species Soup

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Use the table to complete the worksheet
Worksheet
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Evolutionary Classification

• Phylogeny evolutionary relationships among
  organisms
• Evolutionary classification strategy of
  grouping organisms together based on their
  evolutionary history
• Fossil record
• Comparative homologies
• Comparative sequencing of DNA/RNA among organisms
• Molecular clocks

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Molecular Clock

• Allows scientist to compare DNA sequences form
  two species to estimate how long it has been
  since they diverged from a common ancestor

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Phylogenetic Tree Represent hypothesized
evolutionary relationships
Taxonomic Diagrams
Looks like a Branch on a tree
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Cladogram
Taxonomic Diagrams
Which organism is the outgroup
Mammals
Which 2 organism are more closely related
Attempt to trace the process of evolution by
focusing on shared features
Crocodiles and birds
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Refer to page 496 to 497
Worksheet
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Dichotomous Keys Identify Organisms

• 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
  4 b) Are margins of the leaf smooth? Go to 5

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Worksheet
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(No Transcript)
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Domains (Notice the domains on the chart)

• Most inclusive category
• Larger than a kingdom
• There are 3
• Eukarya includes the kingdoms
• Protists, Fungi, Plants Animals
• Bacteria corresponds to the kingdom Eubacteria
• Archaea corresponds to the kingdom
  Archaebacteria

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Slides 17-23

• Is more specific with the classification

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Kingdoms

• (Eubacteria and Archaebacteria) Prokaryotes, with
  or without peptidoglycan in cell walls
• Protista Eukaryotes, diverse, not fungi,
  plants, or animals
• Fungi Eukaryotes, multicellular (except
  yeasts), heterotrophic, chitin in cell walls
• Plantae Eukaryotes, multicellular, autotrophic,
  cell wall containing cellulose
• Animalia Eukaryotes, multicellular,
  heterotrophic, no cell wall

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Kingdom - Eubacteria

• Common name Bacteria
• Unicellular prokaryotes
• Peptidogylcan in cell wall
• Ecologically diverse
• Basic shapes are cocci, bacilli, spirilla
• Reproduce both sexually and asexually

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Kingdom - Archaebacteria

• Cell wall does not contain peptidogylcan
• Cell membrane contains unusual lipids not found
  in other organisms
• Live in extreme environments (devoid of oxygen)
• volcanic hot springs
• brine pools
• black organic mud

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Kingdom Protista

• A classification problem consists of organisms
  that cannot be classified as animals, plants, or
  fungi
• Most unicellular, some colonial and some
  multicellular
• Autotrophic and heterotrophic
• Some move with flagella, pseudopods or cilia
• Animal-like, plant-like and fungus-like groups
• Reproduce by mitosis and meiosis

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Kingdom Fungi

• Most feed on dead, decaying organic matter by
  secreting digestive enzymes into their food
  source then absorbing it into their bodies
• Cell walls of chitin
• Most multicellular some unicellular
• Heterotrophic

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Kingdom Plantae

• Multicellular
• Nonmotile cannot move from place to place
• Cell wall with cellulose
• Mostly photosynthetic autotrophs

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Kingdom Animalia

• Multicellular
• Heterotrophic
• No cell walls or chloroplasts
• Incredible diversity

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Hierarchical Systemof Classification

• From general to more specific

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How Many Kingdoms?
6 Kingdoms
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• Activity What am I?