Classification of Living Things

Four main characteristics to classify organisms

1) number of cells - unicellular or multicellular

2) presence of nucleus - prokaryote or eukaryote

3) how energy is obtained - autotroph or heterotroph

4) mode of reproduction - sexual or asexual

Eight levels of classification

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Autotrophs

Organisms that can make their food, usually through photosynthesis or other chemical processes

Heterotrophs

Organisms that cannot make their own food, so they attain energy by consuming others.

The three domains

Eukarya, Archaea, Eubacteria

Eukarya

The domain that all eukaryotes are classified under

Archaea

The domain that all Archaebacteria are classified under

Eubacteria

The domain that all other bacteria are classified under

The six kingdoms

Bacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.

Animalia

• Multicellular

• Eukaryotic

• Heterotrophs

• Sexually reproduce (some asexual, sea anemones)

• Most animals can move from one place to another

• Dogs, cats, fleas, and sea coral

Plantae

• Multicellular

• Eukaryotes

• Autotrophs, in a few cases (venus flytrap) are heterotrophs

• Some plants produce flowers while others don’t

• Can reproduce sexually or asexually

• Grass, trees, vegetable plants, weeds

Fungi

• Eukaryotes

• Many are multicellular, some unicellular

• All Heterotrophs - feeding on dead or decaying organisms

• Almost everywhere on land, some in water

• Can reproduce sexually or asexually

Protista

• Eukaryotes

• Some unicellular, some multicellular

• Some autotrophs, others are heterotrophs (some can photosynthesize)

• Microscopic - Amoeba, Paramecium, and Euglena

• Can reproduce sexually or asexually

Bacteria

• Unicellular

• Prokaryotes

• Some are helpful or harmful (disease or gut bacteria)

• Some are autotrophs, others heterotrophs

• Asexual

• Live in moderate environments

Archaebacteria

• Unicellular

• Prokaryotes

• Extreme environments - volcanic vents, arctic temperatures, and hot springs

• Can be autotrophic or heterotrophic

• Asexual

• Halophiles, thermophiles, and methanogens

Binomial Nomenclature

formal system of naming species with two parts: genus and species

dent

tooth

bi

2

rubra

red

alba

white

saccharum

sugar

cyano

blue

nigrum

black

helia

sun

quadra

4

cladogram

branching diagram that illustrates the evolutionary relationships among organisms based on shared characteristics