Classification of Organisms

Chapter 17

Biodiversity

• Biodiversity – the variety of organisms considered at all levels from populations to ecosystems.

Taxonomy

• Taxonomy – the science of describing, naming, and classifying particular organisms.

• Taxon – a particular group within the taxonomic system.

The Linnaean System

• Developed by naturalist Carolus Linaeus• Grouped organisms according to their form

and structure (morphology)• Organisms are grouped by similarities.

Levels of Classification

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

• King Philip Came Over For Good Soup • I H L R A E P• N Y A D M N E• G L S E I U C• D U S R L S I• O M Y E• M S

Nomenclature

• Each species has a scientific name• Binomial nomenclature – a two part name– Genus– Species

• Names come from Greek and Latin• Written in italics• Genus (first letter capitalized) species (lowercase)• Examples:– Homo sapiens – E. coli

Systematics

• Phylogenetics – the analysis of evolutionary or ancestral relationships among taxa

• Cladistics – a system of phylogenetic analysis that uses shared and derived characters for grouping taxa

• Shared character – a feature that all members of the group have in common

• Derived character – a feature that evolved only within the group under consideration

• Clade – the group of organisms that includes an ancestor plus all of its descendants

Domains

• Three domains:– Domain Bacteria– Domain Archaea– Domain Eukarya

Domains

• Bacteria– Small, single-celled prokaryotes– Cell walls, no nucleus

• Archaea– Prokaryotes– Live in extreme environments

• Eukarya– Eukaryotic organisms, have a nucleus– Complex, multicellular organisms

6 Kingdoms• The next level of

organization is Kingdoms• There are 6 Kingdoms– Eubacteria– Archaebacteria– Animalia– Plantae– Fungi– Protista

Classwork

• Read page 447- 461• Answer page 450 #s 1-5

Warm-up

1. What is taxonomy? Why bother to classify organisms?

2. What is the purpose of a scientific name?3. What two taxa make up an organisms scientific

name? How is this scientific name correctly written?

4. Write these scientific names correctly:– mola mola – homo sapians – tyrannosaurus rex