Standard S7L1. Students will identify the diversity of living organisms and how they can be compared scientifically. Students will demonstrate the process for the development of a dichotomous key. Classify organisms based on physical characteristics using a dichotomous key of the six kingdom system
This means I will be able to compare organisms based upon their internal and external characteristics. (Phylogeny) I will be able to use a dichotomous key and key out an organism to determine that organism’s scientific name.
I can use a dichotomous key? Learning Target I can use a dichotomous key?
How are living things classified?
Aristotle classified organisms almost 2,000 years ago!
Carolus Linnaeus Introduced a system based on similar structures of organisms.
Taxonomy This is the method of classifying living things or the branch of science that classifies organisms. (It has changed since first introduced by Linnaeus.)
Stop What is taxonomy?
Today we classify based on phylogeny which is the evolutionary history of an organism or how it has changed over time..
Do you know what tool shows phylogeny? Cladogram Page 160
Stop for Phylogeny What is phylogeny? How is a cladogram used?
Today’s classification system separates organisms into six (or five) kingdoms.
Kingdoms are the first and largest category.
The smallest classification category is a species.
Classification Kingdom Phylum Class Order Family Genus Species
How can I remember classification? King Phillip came over for great spaghetti.
Organisms of the same species can mate and produce fertile offspring.
Organisms are named scientifically. The two-word naming system was used by Linnaeus. This system is called: binomial nomenclature.
Binomial Nomenclature The first word identifies the genus, or group of similar species. The second word tells something about the species---what it looks like, where it was found, or who discovered it.
Example of Scientific Names Ovis dalli Marmota monax Pinus palustris
Ovis dalli Did you notice? The first word (Genus) is CAPITALIZED. The second word (species) is not. The scientific name should be written in italics or underlined. Ovis dalli
Scientific Names What is binomial nomenclature? What is the first part of the scientific name? The second part? How are scientific names usually written?
Why use scientific names? To avoid mistakes To show relationships among organisms To give descriptive information To allow information to be easily organized
Tools for identifying organisms: Field Guides----descriptions and illustrations of organisms Dichotomous Keys---detailed lists of identifying characteristics that include scientific names
Creating a Dichotomous Key First, divide the organisms into two large categories; wheels/NO wheels. Then observe features that are similar OR different. You are keying out differences. Make sure there are two descriptions at each step. Give each creature a scientific name. The name will have two parts, will be Latin sounding, and should be descriptive.
Dichotomous Key
Dichotomous Key