100 likes | 228 Views
Classification. How do we classify living things?. All life is classified (organized) using an 8 step classification system. This system was originally created by Carl Linneaus in the 1750’s. In the 1990’s, it was updated based on the research of Carl Woese ( woh-zz ).
E N D
How do we classify living things? • All life is classified (organized) using an 8 step classification system. • This system was originally created by Carl Linneaus in the 1750’s. • In the 1990’s, it was updated based on the research of Carl Woese (woh-zz).
How do we classify living things? • Scientists use the following characteristics to classify organisms into each of the eight “ranks”: • Physical structures (internal and external) • DNA • Structure of the cells from which the organism is made (nucleus, cell membrane, etc.)
How do we classify living things? • There are multiple divisions off of each rank in this classification system. • Together, all of the divisions create the “Tree of Life”
Domain • There are 3 domains of life: • Archea • Single-celled organisms • Cell does not have a definite nucleus • The oldest domain on Earth • Bacteria • Single-celled organisms • Cell does not have a definite nucleus • Eukarya • Single or multi-celled organisms • Cells have a definite nucleus
Kingdom • There are 4 kingdoms in the Eukaryadomain: • Animalia(animals) • Plantae (plants) • Fungi • Protista (microscopic organisms) What kingdoms are the following organisms members of: Turtle Tree Human Mushroom Lady bug Algae
Naming Species • As scientists work their way down the ranking system, each organism falls into one of the existing categories. • An organism’s official scientific name is its genus and species.
Naming Species • Example: A wolf’s scientific name is Canis lupus • Do you know any other scientific names of organisms?
Identifying Organisms • Scientists use dichotomous (or taxonomic) keys to identify organisms. • Dichotomous keys use a series of “either/or” choices to guide the scientist in identifying the organism. • Here is a simple example:
Identifying Organisms • Use the dichotomous key to identify these birds: