CLASSIFICATION OF LIFE

Biology 2

MAIN DISTINCTIONS: What kind of cells make up an

organismEukaryotic: cells with membrane-

bound organelles & cytoskeleton

What kind of cells make up an organismEukaryotic: cells with membrane-

bound organelles & cytoskeletonProkaryotic: cells without

membrane-bound organelles & no cytoskeleton

Eukaryote Prokaryote

Eu – “true” nucleus fungi, protists,

algae are microbial eukaryotes

Unicellular Nucleus and other

organelles present 4 or more

chromosomes Sexual or asexual Larger ribosomes Can cause disease

Pro – “before”; Kary – “nut” or “kernal”

Unicellular No nucleus or

membrane bound organelles

Only 1 chromosome Asexual Smaller ribosomes Can be pathogenic

No archea found that causes disease

What kind of cells make up an organismEukaryotic: cells with membrane-

bound organelles & cytoskeletonProkaryotic: cells without

membrane-bound organelles & no cytoskeleton

How individuals obtain energy & carbonAutotrophHeterotroph

CLASSES OF METABOLISM Autotrophic organisms make food for

themselves from light or other inorganic (nonliving) sourcesPhotoautotrophChemoautotroph

Heterotrophic organisms consume other organisms or waste for foodPhotoheterotrophChemoheterotroph

• sunlight is energy source• CO2 is carbon source• Uses photosynthesis

(Usually plants, algae, bacteria, some archea)

PHOTOAUTOTROPHS

CHEMOAUTOTROPHSuse inorganic molecules

(H2S, NH4, S, H2, NO2, N2, etc.) for energy

CO2 is carbon source(some bacteria, some

archaea)*No sunlight needed!!!

Chromatin, which is an example of a Purple Bacteria, Rhizobium, which is an example of Chemoautotrophic Proteobacteria

PHOTOHETEROTROPHS light is energy source organic molecules are carbon source

some bacteria

Heliobacterium modesticaldum

CHEMOHETEROTROPHS Energy and carbon is from

organic carbon sourceIncludes many bacteria, some

archea, protists, and fungiAll the disease causing organisms

are in this category

Salmonella, which is an example of Chemoheterotrophic Proteobacteria

http://en.wikipedia.org/wiki/File:Troph_flowchart.png

TAXONOMY

ARCHAEA Prokaryotic Most heterotrophic No peptidoglycan in

cell wall

EUBACTERIA Prokaryotic Most heterotrophic

FUNGI Eukaryotic Heterotrophic Cell walls with chitin

PROTISTA (ANIMAL – LIKE) Unicellular (mostly) Eukaryotic heterotrophic

PROTISTA (PLANT – LIKE) Single and multicellular Eukaryotic Autotrophic Differ from plants in reproductive

structures, in some pigments, life history, etc.)

PROTISTA (FUNGUS – LIKE) Eukaryotic Heterotrophic No chitin in cell walls

PLANTAE

Eukaryotic Autotrophic (mostly) Cellulose in cell walls Multicellular

ANIMALIA Eukaryotic Heterotrophic No cell walls Multicellular

VIRUS? Not alive! Have some elements of life:

ProteinsNucleic acids (DNA or RNA)Effect living systems (HIV, Hepititis, bird flu)

Prions – not alive, but are protein-like molecules that affect living thingsMad cowKJD