Classifications of living organisms

The Linnaean system divided living organisms based on Aristotle’s idea of the essential features of living things and on his logic.

Five kingdom classification

Three-domain system

This biological classification divided the celular life forms into:

Bacteria

Eukaryiota

Archaea

Genus

Phylum

Class

Species

Family

Order

The Linnaean system

The main criteria for classification used by Whittaker include cell structure, thallus organisation, mode of nutrition, reproduction and phylogenetic relationships.

Kingdom

Monera

Protista

Fungi

Plantae

Animalia

They don’t have nuclear membrane

RNA markers from bacteria

Considered some of the oldest species in earth.

Cells with bacterial rRNA

No nuclear membrane

organisms whose cells contain a membrane-bound nucleus

They include non-microscopic organisms

Don’t have any clear membrane

They have celular body organization

Noncellulosic

Eukaryotic cell type

Their cell wall is present in some

They do have nuclear membrane

Celular body organization

Eukaryotic cell type

Cell wall present without cellulose

Multicelular body organization

Eukaryotic cell type

Present cell wall

They have organs

Eukaryotic cell type

Absent cell type

They have organ systems

Animals: Organisms able to move on their own

Member of the genus Homo with big forehead and thin skull bones

Hominids with upright posture and large brains

Primates with flat faces and three dimensional vision

Mammals with collar bones and grasping fingers

Chordates with fur or hair and milk glands

Animals with backbone