classification notes. taxonomy: the science of classification why do we need a system of...
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Classification Notes
Taxonomy: the science of classification
• Why do we need a system of classification?– Brings order– Logical means of naming organisms– Scientific names are understood globally
• Common names are regional, not specific, and misleading (puma, cougar, mountain lion are the same animal)
• (ringworm and mealworm are not worms)
Aristotle
• Divided organisms into 2 groups• Plants: classified them on the basis
of structure and size• Animals: divided them on the basis
of where they live
Polynomial System
• A series of additional descriptive names added to the genus name
• Example: the scientific name for a bee using the polynomial system: Apes pubescens, thorace subgriseo, abdomine fusco, pedibus posticis glabris utrinque margine ciliates
Carolus Linnaeus
• Swedish botanist who developed a classification system based on structural features.
Seven taxa:
• Kingdom (largest category)• Phylum• Class• Order• Family• Genus• Species (most specific)
Binomial Nomenclature
• 2 part naming system• Latin (language used)• Genus species (written in italics)• Genus: a noun; always capitalized;
may be abbreviated by using the first letter
Determining Relationship
• Structure• Biochemistry• Development• Phylogeny (evolutionary history)
Human Classification
• Kingdom: Animalia• Phylum: Chordata• Class: Mammalia• Order: Primata• Family: Hominidae• Genus: Homo• Species: sapiens
Our Current System
• Recently changed to 6 kingdoms• The prokaryotic kingdom (Monera)
was split into 2 kingdoms
The Six Kingdoms1. Eubacteria
• Prokaryotes (no nucleus)• Unicellular• Mainly heterotrophs• Reproduce through binary fission• Live in diverse environments• Ex: cyanobacteria, spirochetes
2. Archaebacteria
• Prokaryotes• Unicellular• Mainly heterotrophs• Suited to extreme environments• Ex: halophiles
3. Protista
• Eukaryotic (have a nucleus)• Unicellular• Protozoans (animal-like; heterotrophs)• Algae (plant-like; autotrophs)• Reproduce sexually or asexually• Live in moist habitats• Ex: amoeba, euglena, diatom
4. Fungi
• Eukaryotic• Mostly multicellular• Saprophytes: obtain nutrients through absorption• Reproduce sexually and asexually• Most live in terrestrial habitats• Ex: mushrooms, yeast, puffballs
5. Plantae
• Eukaryotic• Multicellular• Autotrophs• Most live in terrestrial habitats• Reproduce sexually and asexually• Ex: mosses, ferns, flowering plants
6. Animalia
• Eukaryotic• Multicellular• Heterotrophs• Live in terrestrial and aquatic environments• Most reproduce sexually• Ex: worm, starfish, frog, snake, bird, dog