1. CHAPTER 18 CLASSIFICATION
BIOLOGY
CHAPTER 18 CLASSIFICATION
Photo credit: ©Gary Randall/Visuals Unlimited

2. 18.1 Finding Order in Diversity
Classification – grouping of objects or information based on similarities
Taxonomy – branch of biology for grouping and naming organisms

3. Assigning Scientific Names
Scientific Names are written in Latin because:
The language is no longer used
The words stay the same and cannot change since the language is dead
The words only have one meaning

4. Early efforts at naming organisms
Aristotle
Developed the first method of classification
Grouped them into 2 groups: plants and animals
His system was useful but did not group organisms according to their evolutionary history

5. Linneaus
Developed binominal nomenclature system
Binominal Nomenclature – each species has a two part name – genus & species
Based on structural and physical similarities of organisms
He not only named species, he also grouped them into categories.
Each level if called a taxon

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Scientists realized there were enough differences among organisms to make 5 kingdoms:
Monera - bacteria
Protista
Fungi
Plantae
Animalia
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Six Kingdoms
Recently, biologists recognized that Monera were composed of two distinct groups of bacteria
The six-kingdom system of classification includes:
Eubacteria
Archaebacteria
Protista
Fungi
Plantae
Animalia
Monera
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The Three-Domain System
Molecular analyses have given rise to a new taxonomic category that is now recognized by many scientists.
The domain is more inclusive category than any other-larger than a kingdom.
The three domains are:
Eukarya –kingdoms protists, fungi, plants, and animals
Bacteria
Archaea
As new information is gained about organisms in the domains Bacteria and Archaea, they may be subdivided into additional kingdoms.
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9. This diagram shows some of the ways organisms have been classified into kingdoms over the years. The six-kingdom system includes the following kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.

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Domain Eubacteria
unicellular prokaryotes.
Thick or thin cell walls made of peptidoglycan
Ex: E. coli, cyanobacteria
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Domain Archaea
unicellular prokaryotes.
live in extreme environments.
cell walls lack peptidoglycan, and cell membranes contain unusual lipids not found in other organisms.
Ex: thermophiles, haleophiles
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Domain Eukarya
Unicellular and multicellular eukaryotes
This domain is organized into four kingdoms:
Protista
eukaryotic organisms that cannot be classified as animals, plants, or fungi.
unicellular or multicellular
photosynthetic or heterotrophic
Live in moist environments
Ex: paramecium, kelp, slime mold
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Fungi
heterotrophs.
Most fungi feed on dead or decaying organic matter
multicellular (mushrooms) or unicellular (yeasts)
some have cell wall composed of chitin
do not move from place to place
Ex: mushrooms, yeast, black mold
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Plantae
Multicellular
photosynthetic autotrophs.
cannot move from place to place.
cell walls composed of cellulose.
includes cone-bearing and flowering plants as well as mosses and ferns
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Animalia
multicellular
heterotrophic.
do not have cell walls.
can move about
complex organ systems
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22. BIO-QUIZ

23. 18-3
Organisms whose cell walls contain peptidoglycan belong in the kingdom
Fungi.
Eubacteria.
Plantae.
Archaebacteria.

24. 18-3
Multicellular organisms with no cell walls or chloroplasts are members of the kingdom
Animalia.
Protista.
Plantae.
Fungi.

25. 18-3 Organisms that have cell walls containing cellulose are found in
Eubacteria and Plantae.
Fungi and Plantae.
Plantae and Protista.
Plantae only.

26. 18-3
Molecular analyses have given rise to a new taxonomic classification that includes
three domains.
seven kingdoms.
two domains.
five kingdoms.

27. 18-3 Which of the following contain more than one kingdom?
only Archaea
only Bacteria
only Eukarya
both Eukarya and Archaea

28. Eight levels of classification are…
Domain – largest group of classification, a group of related kingdoms
Kingdom – a group of related phyla
Phylum – a group of closely related classes
Class – a group of closely related orders
Order – a group of closely related families
Family – a group of closely related genera
Genus – a group of closely related species
Species
most specific level of classification
a group of organisms that can interbreed and produce fertile offspring

29. Linnaeus's System of Classification
Grizzly bear
Black bear
Giant panda
Red fox
Abert squirrel
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Coral snake
Sea star
Linnaeus’s hierarchical system of classification uses seven taxonomic categories. This illustration shows how a grizzly bear, Ursus arctos, is grouped within each taxonomic category. Only some representative species are illustrated for each category above the species level.
Movie

30. BIO-QUIZ

31. 18-1 Which statement about classification is true?
Biologists use regional names for organisms.
Biologists use a common classification system based on similarities that have scientific significance.
Biologists have identified and named most species found on Earth.
Taxonomy uses a combination of common and scientific names to make the system more useful.

32. 18-1 Linnaeus's two-word naming system is called
binomial nomenclature.
taxonomy.
trinomial nomenclature.
classification.

33. 18-1 Several different classes make up a(an) family. species. kingdom.
phylum.

34. 18-1 A group of closely related species is a(an) class. genus. family.
order.

35. 18-1
Which of the following lists the terms in order from the group with the most species to the group with the least?
order, phylum, family, genus
family, genus, order, phylum
phylum, class, order, family
genus, family, order, phylum

36. Did King Phillip Come Over For Great Spaghetti
Proper way to write a scientific name
All letters are lower case except the genus is capitalized.
Genus and species is underlined or italicized
Ex. eukarya, animalia, chordate, mammalia, primata, hominidae, Homo, sapien

37. Dichotomous Key
A set of paired statements used to help identify organisms
Read each statement and decide which fits your organism
Go to where that statement tells you and read the next two statements
Eventually you will reach a statement that tells you the name of the organism

38. Choose one of the items from the following list: pine tree, clam, rock, robin, tin can, deer, oak tree, mouse, dandelion, Paramecium, bicycle, ant
1. a. Organism is living go to 4.
b. Organism is nonliving go to 2.
2. a. Object is metallic go to 3.
2. b. Object is nonmetallic Rock.
3. a. Object has wheels Bicycle.
3. b. Object does not have wheels Tin Can.
4. a. Organism is microscopic Paramecium.
4. b. Organism is macroscopic go to 5.
5. a. Organism is a plant go to 6.
5. b. Organism is an animal go to 8.

39. 6. a. Plant has a woody stem.........................go to 7.
6. b. Plant has a herbaceous stem Dandelion.
7. a. Tree has needle like leaves Pine Tree.
7. b. Tree has broad leaves Oak Tree.
8. a. Organism lives on land go to 9.
8. b. Organism lives in water Clam.
9. a. Organism has 4 legs or fewer go to 10.
9. b. Organism has more than 4 legs Ant.
10 a. Organism has fur go to 11.
10 b. Organism has feathers Robin.
11 a. Organism has hooves Deer.
11 b. Organism has no hooves Mouse

40. 18.2 Modern Evolutionary Classification
Phylogeny – evolutionary relationships among organisms.
Biologists currently group organisms into categories that represent lines of evolutionary descent, or phylogeny, not just physical similarities.
The higher the level of the taxon, the further back in time is the common ancestor of all the organisms in the taxon.
Organisms that appear very similar may not share a recent common ancestor.

41. Classification Using Cladograms
Cladogram – a branching diagram showing the evolutionary relationships among a group of organisms
Traits that appear in recent parts of a lineage but not in its older members are called derived traits
Derived traits can be used to construct a cladogram
Cladograms help scientists understand how one lineage branched from another in the course of evolution

42. EUBACTERIA
ARCHAEBACTERIA
EUKARYOTES
Fig , p. 327

44. BIO-QUIZ

45. 18-2
Grouping organisms together based on their evolutionary history is called
evolutionary classification.
traditional classification.
cladogram classification.
taxonomic classification.

46. 18-2 Traditional classification groups organisms together based on
derived characters.
similarities in appearance.
DNA and RNA similarities.
molecular clocks.

47. 18-2
In an evolutionary classification system, the higher the taxon level,
the more similar the members of the taxon become.
the more common ancestors would be found in recent time.
the fewer the number of species in the taxon.
the farther back in time the common ancestors would be.

48. 18-2 Classifying organisms using a cladogram depends on identifying
external and internal structural similarities.
new characteristics that have appeared most recently as lineages evolve.
characteristics that have been present in the group for the longest time.
individual variations within the group.

49. 18-2 To compare traits of very different organisms, you would use
anatomical similarities.
anatomical differences.
DNA and RNA.
proteins and carbohydrates.