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
