Biology 11 Taxonomy

Objectives By the end of the lesson you should be able to: State the levels of classification and the man who created the classification system Describe the 3 domains and the 4 kingdoms Discuss the relatedness of organisms based on their classification

Introduction Recall: 1)Life is both similar and diverse 2) Evolution helps us understand who is related to who BUT….How do we organize and make sense of all these different life forms?

Taxonomy The solution to this problem is taxonomy Based upon Carl Linneaus’ system of Binomial Nomenclature.

Classification Problem Any classification system is artificial and based upon the relationships that seem important to the person classifying. This is called Personal Bias.

Classifications The first question in taxonomy is: What are the main divisions? There used to be only 2 kingdoms: plants and animals. Now, the latest classification system employs a “supercategory” called Domains.

Domains

Domain Archaea This includes the Archaebacteria. They include forms of bacteria today that live in the most extreme conditions such as hot springs and sulfur pools. Also includes: Methanogens Halophiles

Domain Archaea Characteristics: Obligate anaerobes Microscopic Prokaryotic Have a cell wall but with no peptidoglycan DNA unique to Archaea Live in extreme environments

Domain Bacteria Includes most of the prokaryotes and all the bacteria (Eubacteria) that we are familiar with. Staphylococcus aureus

Domain Eubacteria Characteristics: Aerobes Prokaryotes Cell walls contain peptidoglycan DNA unique to Eubacteria Microscopic Live in moderate environments

Domain Eukarya This is a huge domain that includes all the eukaryotic organisms. In this domain, we will see and use the more conventional 7 levels of classification. We divide this domain into four kingdoms: Kingdom Phylum Class Order Family Genus Species

Kingdom 1: Protista Eukaryotic cells Uni cell or colonial Motile Autotrophic and heterotrophic Mostly asexual reproduction “Catch-all” <--A protozoan <--An algae

Kingdom 2: Fungi Eukaryotic cells Uni- colonial- or multi-cellular (yeast 1 cell) Non motile Decomposers Sexual and asexual reproduction Spore formers Aspergillius, a bread mold

Kingdom 3: Plantae Multicellular Autotrophic Mostly on land Eukaryotic cells Non motile Asexual and sexual reproduction

Kingdom 4: Animalia Multicellular Heterotrophic Largest group is the Arthropods = 70% of all animals Eukaryotic cells Motile Sexual and asexual reproduction A jumping spider

Conclusion Taxonomy shows us where a species diverged from its relatives. Lets use humans, the house cat, and a maple tree as examples to illustrate this:

Examples of Taxonomic Classification Human Cat Maple Tree Domain Eukarya Eukarya Eukarya Kingdom Animalia Animalia Plantae Phylum Chordata Chordata Tracheophyta Class Mammalia Mammalia Angiospermidea Order Primata Carnivora Sapindales Family Hominidia Felidia Aceridea Genus Homo Felis Acer Species sapiens domesticus rubrum

Poster Time! Make a poster of one of the groups of organisms Be sure your poster is large and correct as these are going to be posted around the room all year! (a great “cheating” tool perhaps?!!?)