Day 4 – Classification Notes

Classifying Organisms Notes Learning Targets: Why do we classify organisms? What language is the classification system written in and why?

Why classify organism? Biologists want to better understand organisms so they organize them. One tool that they use to do this is classification—the grouping of objects or information based on similarities. Taxonomy is the branch of biology that groups and names organisms based on studies of their different characteristics. Biologists who study taxonomy are called taxonomists.

Aristotle’s system The Greek philosopher Aristotle developed the first biological classification system. Two groups: plants and animals. He grouped based on their physical structures.

Linnaeus’s system of binomial nomenclature Carolus Linnaeus developed a method of grouping organisms that is the basis of modern classification systems. Based on physical and structural similarities of organisms. Modern classification systems use a two-word naming system called binomial nomenclature Genus and species = the scientific name The first letter of the Genes is capitalized The species name is all lower case The scientific name is written in Latin

Latin is the universal langauage

Linnaeus’s System of Classification A group or level of organization is called a or taxon (plural: taxa).   Linnaeus’s system of classification uses seven taxa. Modern System Mnemonic Kingdom Phylum Class Order Family Genus Species King Phillip Came Over For Grape Soda

Classification of the Grizzly Bear Linnaeus’s system of classification uses seven taxonomic categories. This illustration shows how a grizzly bear, Ursus arctos, is grouped within each taxonomic category. Only some representative species are illustrated for each category above the species level.

rufus canadensis Domain Kingdom Phylum Class Order Family Genus Species Eukarya Animalia Chordata Mammalia Carnivora Felidae Lynx Bobcat rufus canadensis

Problems with Classifying Classifying species based on their anatomy sometimes posed problems for taxonomists. Scientists debated which of these three organisms were more closely related—crabs (top left), barnacles (bottom left), and limpets (right).

Lets Practice Below are scientific names, correct them! homo sapien ursus Arctos

Lets Practice Below are scientific names, correct them! Homo sapien ursus Arctos

Lets Practice Below are scientific names, correct them! Homo sapien Ursus arctos

Lets Practice Below are scientific names, correct them! LACTRODECTUS MACTANS What is this organism’s common name?

Which two organisms are most closely related? Canis lupus Ursus arctus Ursus nigres Homo sapien

Red Panda

Why is it so hard to classify?

Classify the following organisms Common Name: Humans Poison Ivy E. coli Euglena Shelf Fungus Thermoacidophiles For Each Common Name: Kingdom: Phylum/Division: Class: Order: Family: Genus: Species: Scientific Name: