Classification:

• 1.6 million known and cataloged species.

• Only 5% of all organisms that have lived.

 

Classification- is the arrangement of organisms into orderly groups based on their similarities.

• Classification is also known as taxonomy

Taxonomists- are scientists that identify and name organisms

 

Benefits of Classifying:

• Accurately and uniformly names organisms.

• Prevents misnomers such as starfish and jelly fish that aren't really fish

• Uses same language for all names.

 

Early Taxonomists:

• 2000 years ago, Aristotle was the first taxonomists.

• Aristotle divided organisms

 

Carolus Linnaeus:

• 18th centruy taxonomists

• Calssified organisms by their structure

• father of taxonomy

• Binomial nomenclature

 

Binomial Nomenclature:

• Genus Species

  • latin or greek

  • italicized

  • Capiatlize Genus & lowercase species

  • Underline when writting

 

Taxon/ Taxa- Category:

• heirachy of groups from broadest to most specific

• Domain

  • Kingdom

    • Phylum

      • Class

        • Order

          • Family

            • Genus

              • Species

 

Domains-

• Broadest, most inclusive taxon

• Three domains

• Archea and Eubacteria are unicellular prokarytes

 

Types of Domains:

1. Archea:

   1. Kingdom: Archeabacteria

   2. Probably the first cells to evolve

   3. Live in harsh environments

      1. sewage treatment plants

      2. thermal or volcanic vents

      3. acid hotsprings or geysers

2. Bacteria:

   1. Kingdom- Eubacteria

   2. Some may cause disease

   3. Found in ALL habitats except in the harsh ones

   4. Important decomposers for enviornment

   5. Commerically important in making cottage cheese, yogurt, and buttermilk

3. Protista:

   1. Most are unicellular

   2. Some are multicellular

   3. Some are autotrophic, while others are heterotrophic 

   4. Aquatic

4. Fungi:

   1. Multicellular except yeast

   2. Absorptive heterotrophs

   3. Cell walls made of chitin

5. Animala:

   1. Multicellular

   2. Ingestive

 

Taxons:

• MOst general contain a number of similar species

• Genus Homo is an exception

• Classification based on evolutionary relationships

 

Basis for Modern Taxonomy:

• Homologous Structures 

• Similar embryo development

• Molecular similarity in DNA, RNA, or amino acid sequence of proteins

 

Cladogram- Diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales

Dichotomous Keying:

• Used to identify organisms 

• Characteristic given in pairs