Levels of Classification

Linneaus’ Classification System• Based on a hierarchical

classification that has seven main levels or taxa– Kingdom– Phylum– Class– Order– Family– Genus– Species

general

specific

• Taxon (taxa plural) = a named group of organisms such as phylum Chordata or order Rodentia

• Rank = a level in a classification scheme, such as phylum or order

A Closer Look at the Kingdoms

• First classification system was based on plants and animals

• With the aid of microscopes, new organisms and cell types were discovered

• Now a two-kingdom system is no longer useful

• In this course we will use the six Kingdom system:– Bacteria– Archaebacteria– Protista– Fungi– Plants– Animals

A Closer Look at the Kingdoms

• In this course we will use the six Kingdom system:– Eubacteria– Archaebacteria– Protista– Fungi– Plants– Animals

How are organisms divided into kingdoms?

• The MAIN characteristics used to divide organisms into kingdoms are:– Cell type, complex or simple– Their ability to make food (nutrition)– The number of cells in their body

(multicellularity)– How they reproduce– Presence/absence and type

of a cell wall– Habitat

Review of cell types

• Eukaryote versus Prokaryote cells – can you see the difference?

Kingdom AnimaliaGeneral Characteristics Representative

OrganismsProkaryotic vs. Eukaryotic

Eukaryote, all multicellular

e.g. Sponges, worms. Crayfish, frogs, fish, birds, cats, humans

Heterotrophic vs. Autotrophic

Heterotrophic

Cell Wall Present or absent

Absent

Reproduction Usually sexual, but some asexual

Habitat Terrestrial & aquatic, not extreme

environmentts

Kingdom PlantaeGeneral Characteristics Representative

Organisms

Prokaryotic vs. Eukaryotic

Eukaryotic, all multicellular

e.g. Mosses, ferns, conifers, shrubs, flowering plants

Heterotrophic vs. Autotrophic

Photosynthetic Autotroph

Cell Wall Present or absent

Present – contains cellulose

Reproduction Sexual and Asexual

Habitat Sun exposed environments

Kingdom FungiGeneral Characteristics Representative

Organisms

Prokaryotic vs. Eukaryotic

Eukaryotic, generally

multicellular

e.g. Yeast, bread moulds, mushrooms

Heterotrophic vs. Autotrophic

Heterotrophic

Cell Wall Present or absent

Present – made of Chitin

Reproduction Asexual and sexual

Habitat Mostly terrestrial,

Kingdom ProtistaGeneral Characteristics Representative

OrganismsProkaryotic vs. Eukaryotic

Eukaryote, mostly unicellular

e.g. Algae, amoeba

Heterotrophic vs. Autotrophic

Photosynthetic Autotroph or Heterotroph

Cell Wall Present or absent

Usually none

Reproduction Sexual and asexual

Habitat Aquatic or moist habitats

Kingdom EubacteriaGeneral Characteristics Representative

Organisms

Prokaryotic vs. Eukaryotic

Prokaryote, unicellular

e.g. Bacteria, streptococcus, cyanobacteria, samonellaHeterotrophic vs.

AutotrophicAutotrophic or Heterotrophic

Cell Wall Present or absent

Often present, non-cellulose

Reproduction Asexual

Habitat Almost everywhere Helicobacter pylori

Kingdom ArchaebacteriaGeneral Characteristics Representative

Organisms

Prokaryotic vs. Eukaryotic

Prokaryotic, unicellular

e.g. Methanogens, halophiles (salt loving)

Heterotrophic vs. Autotrophic

Autotrophi and heterotrophic

Cell Wall Present or absent

Present, non-celluose

Reproduction Asexual

Habitat Extreme environments Halobacterium

Guess that Kingdom

• What Kingdom do I belong to?

• Animalia

Charaxes brutus natalensis

Guess that Kingdom

• What Kingdom do I belong to?

• Protista

Paramecium

Guess that Kingdom

• What Kingdom do I belong to?

• Plantae

Athyrium filix-femina

Guess that Kingdom

• What Kingdom do I belong to? I live in this hot spring ?

• Archaebacteria

Guess that Kingdom

• What Kingdom do I belong to?

• Fungi

Amanita muscaria

Guess that Kingdom

• What Kingdom do I belong to?

• Eubacteria

Hyella stella

Dichotomous Keys

• a series of branching “either / or” choices designed to classify specimens

A sample Dichotomous Key