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Kingdoms and DomainsTaxonomy is the science of identifying and classifying organisms. Taxonomy relies on being able to

identify an organism through morphology, behavior and even geographic location.

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Carl Linneaus and Binomial Nomenclature • "father" of modern taxonomy

> introduced a consistent way to group species according to their physical characteristics

> similar species could be grouped into categories he called genera (singular genus)– ex: Urses americanus (black bear) and Ursus maritimus (polar

bear) vs. Phascolarctos cinereus (koala bear)

• He felt that each species should have a binomial unique name (genus and species name)> ex: the briar rose was called Rosa sylvestris inodora seu canina (the

odourless woodland dog rose) and he changed it to Rosa canana

1707­1778

• further grouped species into taxonomic ranks (taxons) based on shared characteristics

• Linneas proposed two kingdoms (the highest taxon): plants and animals

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• How it works:> all species within

the phylum Chordata have a backbone or primitive backbone.

> all members of class Mammalia are warm blooded and feed milk to their young

Modern Taxonomic Levels

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• When protists were discovered, the classification system had to be updated...> Prokaryotes: unicellular organisms that do not have membrane bound organelles

– smallest organisms on Earth

– dominant form of life that inhabit every habitat

– extremely important to life on Earth...but bacteria can have positive or negative effects (Archea were only discovered about 40 years ago; no known diseases are caused by Archae)

– ie. eubacteria and archae

Microbes

Prokaryotic Organelles:­flagella help the cell move

­pilli help attached the cell to other cells or surfaces

­plasmid is a small loop of DNA not essential for cell activities, but provide an advantage to the cell

­cell wall (peptidoglycan) helps with protection and rigidity

­capsule can reduce water loss, resis high temperatures and help keep out antibiotics and viruses

> Eukaryotes: unicellular and small multicellular organisms with organelles– plant and animal cells

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• 6 kingdoms > Animals> Plants> Fungi> Protista (most diverse)> Eubacteria > Archae

• Kingdoms vary in cell structure, metabolism, and reproduction

Kingdoms and Domains

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1.4 Assignment

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S. Pandora Questions