Order From Chaos

1
Order From Chaos
Interest Grabber
Section 18-1

• When you need a new pair of shoes, what do you
  do? You probably walk confidently into a shoe
  store, past the tens or hundreds of pairs of
  shoes you dont want and straight to the kind you
  do want. How do you find them? Shoes are
  organized in the store in categories. People
  organize objects by grouping similar objects
  together.

2
Interest Grabber continued
Section 18-1

• 1. Consider the task facing early biologists who
  attempted to organize living things. How might
  they have begun?
• 2. Suppose that you have been given a green
  plant, stringy brown seaweed, a rabbit, a
  mushroom, a worm, and a grasshopper. Youve been
  asked to organize these things into categories
  that make sense. How would you do it?
• 3. Decide on your categories and write each on a
  sheet of paper. Next to each category, write the
  defining characteristics of that category. Then,
  write in the organisms that fall into each
  category.

3
Section Outline
Section 18-1

• 181 Finding Order in Diversity
• A. Why Classify?
• B. Assigning Scientific Names
• 1. Early Efforts at Naming Organisms
• 2. Binomial Nomenclature
• C. Linnaeuss System of Classification

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Flowchart
Section 18-1
Linnaeuss System of Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
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Figure 18-5 Classification of Ursus arctos
Section 18-1
Coral snake
Abert squirrel
Sea star
Grizzly bear
Black bear
Giant panda
Red fox
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos
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One Big Family?
Interest Grabber
Section 18-2

• How can you determine if one organism is closely
  related to another? It may seem easy, but it
  isnt, and looks are often deceiving. For
  example, roses and orchids are both flowering
  plants, but roses grow on bushes or vines and
  have thorns. Many orchids dont even grow in
  soilthey can grow in trees! Rose and orchid
  blossoms look very different, and roses and
  orchids cannot produce hybrids, or offspring of
  crosses between parents with different traits.

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Interest Grabber continued
Section 18-2

• 1. Do you think roses and orchids are closely
  related? Explain your answer.
• 2. Now, apply the same logic to dogs. Different
  breeds of dogssuch as a Labrador retriever and a
  colliecan breed and produce offspring. So what
  is the difference between the rose-orchid
  combination and the Lab-collie combination?
• 3. What defines a species? Is appearance
  important? What other factors might be considered?

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Section Outline
Section 18-2

• 182 Modern Evolutionary Classification
• A. Which Similarities Are Most Important?
• B. Evolutionary Classification
• C. Classification Using Cladograms
• D. Similarities in DNA and RNA
• E. Molecular Clocks

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Traditional Classification Versus Cladogram
Section 18-2
Appendages
Conical Shells
Crustaceans
Gastropod
Crab
Crab
Limpet
Limpet
Barnacle
Barnacle
Molted exoskeleton
Segmentation
Tiny free-swimming larva
CLADOGRAM
CLASSIFICATION BASED ON VISIBLE SIMILARITIES
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Traditional Classification Versus Cladogram
Section 18-2
Appendages
Conical Shells
Crustaceans
Gastropod
Crab
Crab
Limpet
Limpet
Barnacle
Barnacle
Molted exoskeleton
Segmentation
Tiny free-swimming larva
CLASSIFICATION BASED ON VISIBLE SIMILARITIES
CLADOGRAM
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My Way or the Highway
Interest Grabber
Section 18-3

• Categories that are used to organize an
  assortment of things should be valid. That is,
  they should be based on real information.
  However, categories should be useful, too.
  Suppose that you are taking a survey of traffic.
  You sit at the side of a busy intersection and
  record the vehicles you see in one hour.

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Interest Grabber continued
Section 18-3

• 1. What categories could you use to organize
  your count of vehicles?
• 2. Look at your list of categories. Are all of
  them equally useful?
• 3. Is there more than one valid and useful way to
  organize living things?

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Section Outline
Section 18-3

• 183 Kingdoms and Domains
• A. The Tree of Life Evolves
• B. The Three-Domain System
• C. Domain Bacteria
• D. Domain Archaea
• E. Domain Eukarya
• 1. Protista
• 2. Fungi
• 3. Plantae
• 4. Animalia

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Concept Map
Section 18-3
Living Things
are characterized by
Important characteristics
which place them in
and differing
Domain Eukarya
Cell wall structures
such as
which is subdivided into
which place them in
which coincides with
which coincides with
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Figure 18-12 Key Characteristics of Kingdoms and
Domains
Section 18-3
Classification of Living Things
DOMAIN KINGDOM CELL TYPE CELL
STRUCTURES NUMBER OF CELLS MODE OF
NUTRITION EXAMPLES
Bacteria Eubacteria Prokaryote Cell walls with
peptidoglycan Unicellular Autotroph or
heterotroph Streptococcus, Escherichia coli
Archaea Archaebacteria Prokaryote Cell walls
without peptidoglycan Unicellular Autotroph
or heterotroph Methanogens, halophiles
Protista Eukaryote Cell walls of cellulose in
some some have chloroplasts Most unicellular
some colonial some multicellular Autotroph or
heterotroph Amoeba, Paramecium, slime molds,
giant kelp
Fungi Eukaryote Cell walls of
chitin Most multicellular some
unicellular Heterotroph Mushrooms, yeasts
Plantae Eukaryote Cell walls of cellulose
chloroplasts Multicellular Autotroph Mos
ses, ferns, flowering plants
Animalia Eukaryote No cell walls or
chloroplasts Multicellular Heterotroph
Sponges, worms, insects, fishes, mammals
Eukarya
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Figure 18-13 Cladogram of Six Kingdoms and Three
Domains
Section 18-3
DOMAIN ARCHAEA
DOMAIN EUKARYA
Kingdoms
Eubacteria Archaebacteria Protista Plantae Fungi A
nimalia
DOMAIN BACTERIA
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Video Contents
Videos

• Click a hyperlink to choose a video.
• Panthera leo?, Part 1
• Panthera leo?, Part 2

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Video 1
Video 1
Panthera leo?, Part 1

• Click the image to play the video segment.

19
Video 2
Video 2
Panthera leo?, Part 2
Click the image to play the video segment.
20
Internet
Go Online

• Links from the authors on the search for new
  species
• Interactive test
• For links on classification, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-5181.
• For links on domains of life, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-5183.

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Section 1 Answers
Interest Grabber Answers

• 1. Consider the task facing early biologists who
  attempted to organize living things. How might
  they have begun?
• Students may say that early biologists attempted
  to formulate logical systems for organizing the
  diversity of life.
• 2. Suppose that you have been given a green
  plant, stringy brown seaweed, a rabbit, a
  mushroom, a worm, and a grasshopper. Youve been
  asked to organize these things into categories
  that make sense. How would you do it?
• Students may group the plantlike, sessile
  organisms (the plant, seaweed, and mushroom)
  together, grouping the others as animals.
• 3. Decide on your categories and write each on a
  sheet of paper. Next to each category, write the
  defining characteristics of that category. Then,
  write in the organisms that fall into each
  category.
• Remind students that organizational systems are
  human-made, and there are no right or wrong ones.
  Some, however, are more useful than others.

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Section 2 Answers
Interest Grabber Answers

• 1. Do you think roses and orchids are closely
  related? Explain your answer.
• Students may say that their different growth
  habits and inability to hybridize indicate that
  they are not closely related.
• 2. Now, apply the same logic to dogs. Different
  breeds of dogssuch as a Labrador retriever and a
  colliecan breed and produce offspring. So what
  is the difference between the rose-orchid
  combination and the Lab-collie combination?
• Students may know that all domestic dogs are a
  single species.
• 3. What defines a species? Is appearance
  important? What other factors might be
  considered?
• Students may suggest that a species is defined
  by its members ability to interbreed, regardless
  of appearance.

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Section 3 Answers
Interest Grabber Answers

• 1. What categories could you use to organize
  your count of vehicles?
• Students answers may include, type of vehicle,
  color, age, or manufacturer.
• 2. Look at your list of categories. Are all of
  them equally useful?
• Students may suggest that the usefulness of the
  criteria depends on the intent of the study.
• 3. Is there more than one valid and useful way to
  organize living things?
• Students should conclude that the same set of
  living things could be categorized in several
  ways, depending upon the criteria used.

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End of Custom Shows

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