classification chapter 17
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Classification Chapter 17. Species of Organisms. Almost 2 million species of organisms have been described Thousands more are discovered each year The total number of species ranges from 5 to 30 million. What is Classification?. - PowerPoint PPT PresentationTRANSCRIPT
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Classification Chapter 17
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•Almost 2 million species of organisms have been described
•Thousands more are discovered each year
•The total number of species ranges from 5 to 30 million
Species of Organisms
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What is Classification?Classification is the
arrangement of organisms into orderly groups based on their similarities
Classification is also known as taxonomy
Taxonomists are scientists that identify & name organisms
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Benefits of Classifying
•Accurately & uniformly names organisms •Prevents misnomers such as starfish & jellyfish that aren't really fish •Uses same language (Latin or some Greek) for all names
Sea”horse”??
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Confusion in Using Different Languages for Names
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Latin Names are Understood by all Taxonomists
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Early Taxonomists•2000 years ago, Aristotle was the first taxonomist•Aristotle divided organisms into plants & animals•He subdivided them by their habitat --Ex) land, sea, or air dwellers
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Carolus Linnaeus1707 – 1778
•18th century taxonomist
•Classified organisms by their form and structure
•Developed 7 levels of classification
•Developed naming system still used today
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Carolus Linnaeus•Called the “Father of Taxonomy”•Developed the modern system of naming known as binomial nomenclature- two-word name (Genus & species)
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Standardized Naming
Binomial nomenclature uses:•Genus species•Latin or Greek•Italicized in print•Capitalize genus, but NOT species•Underline when writing
Turdus migratorius
American Robin
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Binomial Nomenclature
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Classification Groups•Taxon ( taxa-plural) is a
category into which related organisms are placed
•There is a hierarchy of groups (taxa) from broadest to most specific
•Domain, Kingdom, Phylum, Class, Order, Family, Genus, species
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Hierarchy-Taxonomic Groups
DomainKingdom
Phylum Class Order Family
Genus Species
BROADEST TAXON
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KingPhillipCameOverForGoodSpaghetti
!
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Two Modern Systems
Six Kingdom System
Three Domain System
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The Six Kingdoms:
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• The prefix archae - comes from the Greek word "ANCIENT"
• Unicellular & Prokaryotic• Some are autotrophic and some are heterotrophic
• Live in extreme environments
Sewage treatment
plants, thermal
vents, etc.
KingdomArchaebacteria
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Kingdom Eubacteria
• Cause human diseases, are present in almost all habitats on earth
• Many bacteria are important environmentally and commercially. Live in the
intestines of animals
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Kingdom Protista“The odds and ends kingdom” Dumping ground of organisms that don’t fit into the other kingdomsEukaryoticUnicellular or Multicellular
Ex) Algae, Slime molds, Diatoms, and Protozoa
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Kingdom Fungi•Multicellular,
except yeast•Absorptive
heterotrophs (digest food outside their body & then absorb it)
•Decomposers Ex) yeast, mold,
mildew, & mushrooms
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Kingdom Plantae•Multicellular•Autotrophic•Absorb sunlight to make glucose – Photosynthesis•Cell walls made of cellulose
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Kingdom Animalia
•Multicellular• Ingestive
heterotrophs (consume food & digest it inside their bodies)
•Feed on plants or animals
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• Broadest, most inclusive taxon
Three domains:1.Archaea2.Eubacteria are unicellular
prokaryotes (no nucleus or membrane-bound organelles)
3.Eukarya are more complex and have a nucleus and membrane-bound organelles
Domains
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Domain Eukarya includes:•Protista (protozoans,
algae…)•Fungi (mushrooms,
yeasts …)•Plantae (multicellular
plants)•Animalia (multicellular
animals)
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Skills Practice1. List the levels of classification
from most broad to most specific.2. What type of organisms are
found in the kingdom Archaebacteria? Are these organisms unicellular or multicellular?
3. What 4 kingdoms are in the Domain Eukarya?
4. What is the difference between an autotroph and a heterotroph? Give an example of each.
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Classification is based on evolutionary relationships: •Homologous structures
(same structure, different function)
•Similar embryo development
•Similarity in DNA, RNA, or amino acid sequence of Proteins
30Homologous Structures show Similarities in
mammals.
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Similarities in Vertebrate Embryos
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• Phylogenetics- the analysis of the evolutionary
or ancestral relationships among a taxon (group).
• Phylogenetic diagram (tree)- a branching tree
that indicates how closely related species are.
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CladogramDiagram showing how organisms are
related based on shared, derived characteristics such as feathers, hair, or scales
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Primate Cladogram
Let’s Create A Cladogram from the following:
Derived Characterssegmente
d jaws hair placenta multicellula
r limbs
kangaroo + + + - + +
earthworm
+ - - - + -
amoeba - - - - - -
lizard + + - - + +
cat + + + + + + sponge - - - - + -
salmon + + - - + -
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Dichotomous Keying•Used to identify
organisms•Characteristics given in
pairs•Read both
characteristics and either go to another set of characteristics OR identify the organism
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Example of Dichotomous Key
1a Tentacles present – Go to 21b Tentacles absent – Go to 32a Eight Tentacles – Octopus2b More than 8 tentacles – 33a Tentacles hang down – go to 43b Tentacles upright–Sea Anemone4a Balloon-shaped body–Jellyfish4b Body NOT balloon-shaped - 5
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