General Classification

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See also User:Atcovi/Science/Biology Terms
See also User:Atcovi/Science/Introduction to Science, Experimental Design, and Graphing

Introduction to Classification[edit | edit source]

  • For 3.5 billion years, life on Earth has been constantly changing. Natural Selection and other processes have led to diversity of organisms.
  • Why classify organisms? So that we have an organized system to help us study about the diversity of life.
  • What is classification? Grouping of organisms based upon their similarities.

Taxonomy[edit | edit source]

  • Taxonomy is the branch of science that groups and names living organisms based on their relationships inferred by shared characters.
  • Aristotle was the first scientist who attempted to classify organisms. He subdivided plants into three groups: shrubs, herbs and trees. He subdivided animals into their habitat: air, water and land.
  • The problem with Aristotle's system was that it wasn't accurate enough... for example: It placed organisms that all fly in the same category: Bees, birds, and bats are related to each other!

Linneaus' System & Modern Evolutionary Classification[edit | edit source]

Carolus Linnaeus
  • The foundation of today's modern classification actually goes back to Swedish botanist Carolus Linnaeus (1707-1778).
  • Linneaus classified organisms according to their physical and structural similarities.
  • Linneaus used a two word naming system called Binomial Nomenclature to identify species. The first name is the genus and the second name is a descriptive word called the species.

  • What is the correct way to write a scientific name? Give an example: Genus species
    • (Write "Genus" (capitalize), then species--either italicized/underlined).

  • What language is used for scientific names? Latin Why?
  1. Latin is a dead language, so the language can't be changed.
  2. Many organisms have share common names/nicknames, so its good for them to have different scientific names.

Classification[edit | edit source]

How Living Things are Classified[edit | edit source]

The 7 taxas

Organisms are ranked or grouped in groups, from very broad to very specific. These groups are known as taxas.

The Kingdoms
  1. Archaebacteria
  2. Eubacteria
  3. Protista
  4. Fungi
  5. Plantae
  6. Animalia

Each organism is subdivided into 7 categories called taxas. List each taxa below from most amount of organisms to least amount of organisms:

  1. Domain
  2. Kingdom
  3. Phylum
  4. Class
  5. Order
  6. Family
  7. Genus
  8. Species
What is the sentence to help you out with thee 7 taxas? Did King Phillip Come Over From German Soil?
  • Most organisms? Domain
  • Least organisms? Species
  • Which grouping is a subdivision of the phylum? Class
  • A group of similar orders is called a what? Class
  • A Genus is a group of similar species.
  • Kingdom Plantae may not use the term, phylum, for a group of similar classes, instead it might use the taxa term, divisions.
  • Species: Group of organisms in a population that can interbreed and produce fertile offspring.

The Three-Domain System/Six-Kingdom System[edit | edit source]

Based upon recent evidence, the five-kingdom system of classification has now expanded to six kingdoms. The kingdoms, archaebacteria and eubacteria, used to be one kingdom called the Monera Kingdom.

  • Molecular Analyses have given rise to a new taxonomic category that is now recognized by many scientists.
List the three domains and which kingdoms belong to each domain below

-Domain Bacteria
--Kingdom Eubacteria

-Domain Archaea
--Kingdom Archaebacteria

-Domain Eukarya
--Kingdom Protista
--Kingdom Fungi
--Kingdom Plantae
--Kingdom Animalia

Diagrams and Keys used to Classify Organisms[edit | edit source]


Dichotomous Key- Series of paired statements that describe physical characteristic of different organisms.

Cladogram- Diagram that shows the evolutionary relationships among a group of organisms.