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Classification of Organisms. Mrs. Wolfe. How do we keep track of them all?. Estimated 10 – 30 million organisms on earth Taxonomy – the science of naming and classifying organisms Scientists began using taxonomy in the middle ages. What is Taxonomy?.
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Classification of Organisms Mrs. Wolfe
How do we keep track of them all? • Estimated 10 – 30 million organisms on earth • Taxonomy – the science of naming and classifying organisms • Scientists began using taxonomy in the middle ages.
What is Taxonomy? • We name organisms using a system called binomial nomenclature. • Carolus Linnaeus • Swedish biologist • Catalogued organisms • Developed a way to name them
Binomial Nomenclature • A two-word naming system • Each organism has two words for its name and we call this its scientific name. • Example: • Quercus ruba common name: Red oak acorn • First name is capitalized. This is the Genus of the organism. • Second name is lowercase. This is the Species of the organism. • Both words in italics or underlined.
More examples • Erithacus rubicula • Great Britain robin • Turdus migratorius • North American robin • Homo sapiens • Human • Remember: Genus species or Genus species
How did he name all of those organisms? He first grouped them by likeness and named the groups. He continued to make smaller and smaller groups until he was down to a single species. Kingdom Phylum Class Order Family Genus Species Linnaes’ system
Species • The final category, that cannot be divided further, is species. • A species is a group of organisms that can interbreed with each other and cannot interbreed with other groups of organisms.
Suppose we found an organism in the woods….. • What kind of organism is it? • Scientists have several tools to identify the organism: • Dichotomous keys • Field Guides
Dichotomous Key • Example: Identify these objects 1a. Long, tubular object…………….…..go to number 2 b. Short, non-tubular object ………..…go to number 4 2a. Constructed from plastic………..…..go to number 3 b. Constructed from wood…………….…..……pencil 3a. Produces yellow color……………….….highlighter b. Produces a black ink…………………….…...…pen 4a. Is rectangular with a metal blade….pencil sharpener b. Is made of silver metal…….………..……paper clip
However, ….. • A dichotomous key identifies the scientific name of an organism. Try to identify the organisms in your handout using your dichotomous key. • Notice how you determine a SCIENTIFIC NAME for each organism!
Field Guides • Books you can use to identify an organism while you’re out. • You see an animal track. You can use the book to determine the organism that made the track.