taxonomy

Bird's Eyeview of the Living World

The Six Kingdoms of Classification

  • Historical Context

    • 1700’s: Linnaeus classified all life into 2 kingdoms: Plants and Animals.

    • As understanding of organism diversity expanded, more kingdoms were recognized.

    • Currently accepted classification includes 6 kingdoms.

The Six Kingdoms

  • Kingdoms are the broadest taxa in biological classification, following the hierarchy: Kingdom, Phylum, Class, Order, Family, Genus, Species (KPCOFGS).

  • Kingdoms:

    • ANIMALIA: Multicellular, eukaryotic organisms.

    • PLANTAE: Multicellular, eukaryotic organisms.

    • FUNGI: Multicellular or unicellular, eukaryotic organisms.

    • PROTISTA: Eukaryotic organisms that can be unicellular or multicellular.

    • EUBACTERIA: Unicellular, prokaryotic organisms.

    • ARCHAEBACTERIA: Unicellular, prokaryotic organisms.

Taxonomy and Cell Types

  • Taxonomy organised by:

    • Type of cells.

    • Ability to produce food (autotrophic vs. heterotrophic).

    • Cellular complexity (unicellular vs. multicellular).

  • Organisms Overview:

    • Archaebacteria: Unicellular, prokaryotic.

    • Eubacteria: Unicellular, prokaryotic.

    • Protists: Mostly unicellular, some multicellular, eukaryotic.

    • Fungi: Multicellular or unicellular, eukaryotic.

    • Plants: Multicellular, eukaryotic.

    • Animals: Multicellular, eukaryotic.

Key Terminology

  • Getting Food:

    • Autotrophs: Organisms that make their own food.

    • Heterotrophs: Organisms that obtain food from other sources.

  • Type of Cells:

    • Prokaryotic: No nucleus, circular DNA (plasmid), smaller in size, contain ribosomes.

    • Eukaryotic: Has a nucleus and organelles, DNA in chromosomes, larger in size.

  • Body Type:

    • Unicellular: Made of one cell.

    • Multicellular: Made of multiple cells, can have specialized functions.

  • Reproduction:

    • Sexual: Involves male and female parents.

    • Asexual: Involves only one parent.

Details of Each Kingdom

Kingdom Archaebacteria

  • Cell Type: Prokaryote

  • Number of Cells: Unicellular

  • Nutrition: Autotroph or Heterotroph

  • Location: Extreme environments (e.g., volcanoes, deep-sea vents, Yellowstone hot springs).

  • Examples: Methanogens, Thermophiles (ancient bacteria).

Kingdom Eubacteria

  • Cell Type: Prokaryote

  • Number of Cells: Unicellular

  • Nutrition: Autotroph or Heterotroph

  • Examples: Escherichia coli (E. coli), Streptococcus.

  • Chemical Makeup: Different from Archaebacteria.

Kingdom Protista

  • Cell Type: Eukaryote

  • Number of Cells: Mostly unicellular, some multicellular

  • Nutrition: Autotroph or Heterotroph

  • Examples: Amoeba, Paramecium, Euglena.

  • Characteristics: Diverse, referred to as the “odds and ends” kingdom.

Kingdom Fungi

  • Cell Type: Eukaryote

  • Number of Cells: Mostly multicellular, some unicellular

  • Nutrition: Heterotroph (decomposers).

  • Examples: Mushrooms, yeast, mildew, mold.

Kingdom Plantae

  • Cell Type: Eukaryote

  • Number of Cells: Multicellular

  • Nutrition: Autotroph

  • Examples: Mosses, ferns, conifers, flowering plants.

Kingdom Animalia

  • Cell Type: Eukaryote

  • Number of Cells: Multicellular

  • Nutrition: Heterotroph

  • Examples: Sponges, worms, insects, fish, mammals.

Summary of the Six Kingdoms

  • Eubacteria: "True" bacteria (prokaryotic).

  • Archaebacteria: "Ancient" bacteria (prokaryotic).

  • Protista: Diverse and unique organisms (eukaryotic).

  • Fungi: Decomposers of dead matter (eukaryotic).

  • Plantae: Stationary, photosynthetic organisms (eukaryotic).

  • Animalia: Mobile, heterotrophic organisms (eukaryotic).