Classifying Organisms

Introduction

There have been many different ideas about how to classify living things. Aristotle placed all organisms into two large groups--plants and animals. Carolus Linnaeus placed all organisms into two main groups, called Kingdoms. In 1969 an American biologist proposed a five-kingdom system for classifying organisms that included kingdoms Monera, Protista, Plantae, Fungi, and Animalia. The current system used for classifying organisms is called systematics. Systematics uses all the evidence that is known about organisms to classify them.

Task

By the end of this Webquest, students will: 

  • learn how to classify organisms by physical characteristics. 
  • know the taxonomic hierarchy, domain, kingdom, phylum, class, family, genus, and species. 
  • increased knowledge about how living things are classified all around the world. 
Process

Organisms are classified into one of three domains - Bacteria, Archaea, and Eukarya. 

Scientific Names

When Linnaeus grouped organisms into kingdoms, he also developed a system for naming organisms. His system of binomial nomenclature gives each organism a two-word scientific name, such as Ursus arctos for a brown bear. A(n) species is a group of organisms that have similar traits and produce fertile offspring. In a scientific name, the first word is the organism’s genus such as Ursus. The second word in a scientific name identifies the species. Similar species are grouped into one genus. Similar genera are grouped into families and then into orders, classes, phyla, kingdoms, and domains. Each species has its own scientific name, which is the same all over the world.

Classification Tools

A(n) dichotomous key is a series of descriptions arranged in pairs that can be used to identify an unknown organism. The chosen description leads to another pair of descriptions or to the identification of the organism. A(n) cladogram is a branched diagram that shows the relationships among organisms. New characteristics appear before each branch.

Evaluation
Conclusion

Organisms, living things, are classified through characteristics like body type and the process of which the organisms are able to reproduce. Scientists use the same system of naming organisms all over the world. The language that is used is Latin. Each species has its own scientific name. Organisms are divided into domain, kingdom, phylum, class, order, family, genus, and species. 

Credits
Teacher Page

Targeted Audience: 6th Graders 

Unit: Classifying Organisms