Classification and Taxonomy Notes

Classification

• Binomial System of Nomenclature:

  • An internationally recognized method of naming species.
  • Started by Carolus Linnaeus (Father of Taxonomy).
  • Used to name newly discovered species.
  • Must be approved by a congress of scientists in the field.
  • Example: Homo sapiens
    • If you mention scientific name, it has to be infull in title and first paragraph.
    • Abbreviated as H. sapiens
    • IF write a scientific name, underline it. If you type, you italicize

• Species:

  • In order to be in the same species, organisms must be able to interbreed and produce fertile offspring.
  • Very similar characteristics.

• Genus:

  • Group of similar species.

• Taxon:

  • A unit used to classify an organism (plural: taxa).
  • There are seven taxa.

Taxa

• Mnemonic Device: Did King Phillip Come Over For Good Spaghetti

• Taxon: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

  • Domain: Most inclusive
  • Species: Most exclusive

• Genus and accompanying higher taxa consist of all species that have evolved from one common ancestral species.

• Homo Sapien Classification:

  • Domain: Eukarya
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Mammalia
  • Order: Primates
  • Family: Hominidae
  • Genus: Homo
  • Species: Sapiens

• Groups of species can be reclassified when new evidence shows that a previous taxa contains species that have evolved from different ancestral species.

Phylogeny

• Evolutionary relationship between organisms.
• Cladogram: Branching diagram.
  • Everything before each tic/trait is the common ancestor.
  • Each tic is called a derived trait.

*Example Cladogram (Traits and Organisms):
* Vertebrae (common ancestor)
* Derived Traits:
* Four limbs
* Amniotic egg
* Pre-orbital fenestra
* Hair
* Organisms (example):
*Vertebrae
* Sharks
* Ray-finned fish
* Amphibians
* Rodents & rabbits
* Dinosaurs
* Crocodiles and birds
* Primates

• Nodes: Intersection where branching occurs.
• Bony skeleton called nodes
• Vertebrae common ancestor

Domain

• All living organisms are classified into 3 domains:
  • Eubacteria
  • Archaea
  • Eukarya

1. Eubacteria

• Members are called Bacteria (true).
• Cell Type: Prokaryotic
• Cell Wall: Yes, made of peptidoglycan
• rRNA: 70S ribosome
• Other: DNA is not wrapped around histone proteins; example: Cyanobacteria.

2. Archaea

• Members are called Archean.
• Cell Type: Prokaryotic
• Cell Wall: Yes, not made of peptidoglycan
• rRNA: 70S ribosome; amino acid sequence of the ribosome is similar to Eukarya.
• Other:
  • Extremophiles: Live in harsh environments.
    • Thermophiles: High temperature
    • Halophiles: High salt
    • Methanogens
  • DNA wrapped around proteins similar to histone

3. Eukarya

• Cell Type: Eukaryotic (true nucleus)
• Cell Wall: Some (Plants - cellulose); no peptidoglycan
• rRNA: 80S ribosome
• Other: DNA wrapped around histone proteins

Eukarya Domains

• Protista
• Fungi
• Plantae
• Animalia

1. Protista

• Simple, predominantly unicellular eukaryotic organisms.
• Examples include:
  • Slime mold
  • Euglena: live in fresh water contractile vacuole - prevents plasmalyzation- euglena; contrasts to previous excess water
  • Amoeba

2. Fungi

*Unicellular or multicellular organisms with eukaryotic cell types.
*Saprotrophs: engages in detritus
*Detritus - dead organic matter
*Detritivores - Worms.
* The cells have cell walls but are not organized into tissues.
* They do not carry out photosynthesis and obtain nutrients through absorption.
*Examples include:
* Yeast
* Mold
* Mushrooms

3. Plantae

• Multicellular organisms composed of eukaryotic cells.
• The cells are organized into tissues and have cell walls.
• They obtain nutrients by photosynthesis and absorption.
• Examples include:
  • Moss
  • Ferns
  • Pine Trees

4. Animalia

• Multicellular organisms composed of eukaryotic cells.
• The cells are organized into tissues and lack cell walls.
• They do not carry out photosynthesis and obtain nutrients primarily by ingestion.
• Examples include:
  • Sponges
  • Worms
  • Axolotl
  • Sea anemone

Plantae Kingdom

*Bryophyta:
*Have rhizoids
*Space, nutrients, low to ground
*Lack vascular tissue
*Coniferophyta:
*Spindle-like to save water
*Save leaf from environment
*Cones release spores to foilize sped
*Angiospermophyta:
*most varied
*Plant seed one
*most intelligent

Animalia Kingdom