Unit:%20Classification%20How%20are%20living%20things%20classified?%20SB3b.%20Examine%20the%20evolutionary%20basis%20of%20modern%20classification%20systems

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Unit ClassificationHow are living things
classified?SB3b. Examine the evolutionary basis
of modern classification systems
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Unit ClassificationHow are living things
classified?SB3b. Examine the evolutionary basis
of modern classification systems
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How are living things classified?

• Classification grouping of objects,
  information, objects organisms based on
  similarities

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How are living things classified?

• Taxonomy grouping and naming of
  organisms(living things)
• - Linnaeus developed the present method of
  classification
• - classified organisms by their physical and
  structural similarities-THEN
•  NOW-scientists use evolutionary relationships to
  classify organisms

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How are living things classified?

• Organisms are named using a ___2_____ - word
  system (scientific names)binomial nomenclature
• Rules Scientific names are always italicized or
  underlined
• Scientific names are Latin
• Scientific names are made of 2 words
• Genus name is the first word it starts with
  capital letter
• - species name is the __second_ word it
  starts with a lowercase letter
• Ex Homo sapiens Humans OR Ursus
  maritimus Polar Bear

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How are living things classified?

• Organisms are classified ( organized) based on
• 1) Physical similarities (ex homologous
  structures)
• 2) Fossil evidence that show common ancestry
• 3) similarities in embryological stages (ex
  embryos of different species have
• tails gills)
• 4) similarities in DNA and
• proteins
• (molecular biology/
• biochemistry)

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How are living things classified?

• Linnaeus System of Classification
• Linnaeus system has 7 taxa a.k.a. levels
• ( taxon singular)

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• Taxon Pneumonic Example
  Humans
•  Kingdom _________________ Animalia
• Phylum _________________ Chordata
• Class _________________ Mammalia
• Order _________________
  Primate
• Family _________________ Hominidae
• Genus _________________
  Homo
• Species _________________ sapiens

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How are living things classified?

• The more classification levels 2 organisms
  have in common, the more closely related they
  are
• The less classification levels 2 organisms
  have in common, the more __distantly___ related
  they are

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3 Domains of Life

• Domains-more general than kingdoms
• 1. 2.
  3.

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Sizes in biology
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Are viruses classified?
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Are viruses living?

• Characteristic of Life Virus
  Cell
• Growth No Yes
• Cells No Yes
• Homeostasis No Yes
• Energy No Yes
• Mutation Yes Yes
• Nucleic Acid DNA or RNA DNA
• Reproduction only within host cell
  independently by
  cell division
• Structure DNA or RNA protein Cell
  membrane wrapped in protein
  cytoplasm, ribosomes