Chapter 14 Lesson 2 Classifying Species

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Chapter 14 Lesson 2Classifying Species
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Classification

• grouping objects or organisms based on
  similarities

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• 1. Taxonomy the science of classifying
  organism s
• - similarities among organisms indicates that
  they are somehow related
• 2.  What categories are used to classify
  organisms?
• a.  Homologies similar structures or similar
  biochemistry that results from a common ancestor
• b. Embryonic development development of fetus
• c.  Genetics DNA and gene similarities
• d.  Evolutionary history

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History of Classification Systems

• 1.  Aristotle - 350 BC
• a.  Developed the 1st widely accepted
  classification system
• b. Divided organisms into plants or animals
• c. Plants were further divided by size and
  structure (trees, shrubs, herbs)
• d. Animals were classified by where they lived
  (land, sea, or air)

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Early Classification

• Previous classification system 2 kingdom
  Plantae and Animalia
• Declared inadequate
• Next system added
• Protista - microorganisms and bacteria
• Fungi mushrooms, molds, and yeasts

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Carolus Linneaus

• Classification system based on physical and
  structural similarities of organisms
• b.  System called Binomial nomenclature two
  word names
•               i.   1st part Genus
•               ii. 2nd part Species
• c. Latin
• d.  Ex. Humans Homo sapiens
• e. Scientific names must be in italics or
  underlined
• f. Genus name is capitalized, species name is
  lower case

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Scientific Names

• i.  common names can be misleading because they
  vary (language or location)
• ii.  scientific names are recognized worldwide
• iii. scientific names indicate relationships
• 1.   Maple Trees Genus Acer
• 2. Acer rubrum red maple
• 3.   Acer saccharum sugar maple

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Classification Groups

• Taxon a group of organism (plural taxa)
• Seven Classification Taxa
• 1.   Kingdom largest taxa, includes many types
  of organism with some similarities
• 2.    Phylum
• 3.    Class
• 4.    Order
• 5.    Family
• 6.    Genus
• 7.   Species smallest category, only includes
  one type of organism

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• Similar species grouped in one Genus
• Similar Genus are grouped in one family so on
• Categories always based on similarities among
  organisms
• Ex. Phylum Chordata backbones
• Class Mammal warm-blooded, hair or fur, produce
  milk for young
• Order Carnivore - sharp teeth, claws, hunt and
  eat meat
• As we learn more, the classification of an
  organism can change
• Species a group of organisms that can mate and
  produce fertile young

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Six Kingdoms

• Differ in cell structure
• o  Unicellular vs. multicellular
• o  Prokaryotic vs. Eukaryotic
• Differ in means of obtaining energy
• autotrophic vs. heterotrophic

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3. Protista (protists)

• a.  Eukaryotic
• b.   Single celled (but some, like algae, are
  multicellular)
• c.   Most are microscopic
• d.   Do not have complex organ systems
• e.   2 main divisions
• 1.    Algae autotrophic
• a.     Plant-like, but do not have leaves or
  stems
• b.    Important base of many food chains
• 2.    Protozoa heterotrophic
• a.    Animal-like
• b.     Amoeba, paramecium

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4. Fungi

• a. Eukaryotes
• b. Unicellular (yeasts) and multicellular
  (mushrooms and molds)
• c.  Heterotrophic mainly decomposers
• d.  Cell walls contain chitin a long-chain
  polymer of beta-glucose that forms a hard,
  semitransparent material
• e.   Absorb food through cell walls
• f.   Develop from spores, do not move

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5. Plantea (Plants)

• a. Eukaryotic
• b. Multicellular
• c.  Autotrophic (photosynthetic)
• d.  Cell walls contain cellulose
• e.  Tissues, organs, organs systems
• f. Do not move around
• g. Trees, moss, ferns, grass

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6. Animalia (animals)

• a. Eukaryotic
• b.  Multicellular
• c.  Heterotrophic
• d.  Able to move at some time in life
• e.  No cell walls
• f.   Tissues, organs, organ systems Ex. Nervous,
  circulatory, muscle systems
• g.   Ex. Hydra, sponges, coral, fish, insects,
  birds, frogs, mammals

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Biological Keys

• also called dichotomous (2 branched) key
• series of paired (2) statements that compare or
  describe characteristics of organisms in order to
  identify them
• To use a key you always start with the first set
  of sentences, read the description, compare it to
  your organism, then follow the instructions to
  continue the key
• You will work to find the name through
  descriptions until the name of your organism is
  given

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How to make a dichotomous key

• divide your samples into 2 groups using one
  characteristic
• write a set of 2 sentences describing the
  characteristics you have used to divide your
  object/organisms
• Characteristics must be objective (ex. 5 cm) not
  subjective (ex. Short/long)

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• Example
• 1.Has straight sidesgo to 2
• Does not have straight sides.go to 4
• 2. Has 3 sides triangle
• Has more than three sidesgo to 3
• 3. Has 4 sides ..Square
• Has more than 4 sides ..star
• 4.Diameter is same all over.circle
• Diameter varies.oval