Study of Life Classification 2006-2007
The history of Classification Objectives: Explain how to write a scientific name using binomial nomenclature Summarize categories used in biological classification
What variety! What similarity! Diversity of Life there are so many different creatures on Earth why are there differences? Unity of life all creatures have similarities common characteristics why are they so alike?
Organizing the world of organsims The Tree of Life organize creatures by structure & function how they are built how they live organize them into groups of closely related creatures
Classification Groupings of different types of organisms based upon similarities in structure and evolutionary relationships
Taxonomy the branch of biology that groups and names organisms based on studies of their different characteristics.
Taxonomy: A useful tool Grouping organisms on the basis of their evolutionary relationships makes it easier to understand biological diversity. can be a useful tool for scientists who work in agriculture, forestry, and medicine. It often happens that the discovery of new sources of lumber, medicines, and energy results from the work of taxonomists.
Taxonomy: A useful tool Anyone can learn to identify many organisms using a dichotomous key. A key is made up of sets of numbered statements. Each set deals with a single characteristic of an organism, such as leaf shape or arrangement.
How Classification Began Aristotle’s system: (384-322 B.C.) classified all the organisms he knew into two groups: plants and animals. Carolus Linnaeus (1707-1778) system was based on physical and structural similarities of organisms.
Carolus Linnaeus The Linnean system Homo sapiens proposed in 1700s each species has a 2 part name genus species Homo sapiens
Latin binomial 2 part scientific name Genus — larger group to which organism belongs always capitalized species — specific name for that organism always lowercase example: Linnaeus named humans Homo sapiens means “wise man” — perhaps in a show of hope & optimism
Genus groupings Classify organisms into broader groups Species that are closely related are grouped into the same genus Leopard Panthera pardus African lion Panthera leo Tiger Panthera tigris
Why not use common names? Misleading starfish dragonfly Confusing blue jay, blue coat, corn thief dog, perro, chien I swim, but I’m still a bird!
Why not use common names? Misleading starfish dragonfly Confusing blue jay, blue coat, corn thief dog, perro, chien I swim, but I’m still a bird!
Why not use common names? But they all have only one scientific name! Pisaster ochraceus Pyrrhosoma nymphula Cyanocitta cristata
Ch. 17. section 3 Objectives: Compare major characteristics of the three domains Differentiate among the six kingdoms Classify organisms to the kingdom level
How Living Things Are Classified A group of organisms is called a taxon Organisms are ranked in taxa that range from having very broad characteristics to very specific ones. The broader a taxon, the more general its characteristics, and the more species it contains.
THE DOMAINS OF LIFE Arranging life into kingdoms is a work in progress For several decades, biologists have classified life into five kingdoms MONERA PROTISTA PLANTAE FUNGI ANIMALIA Earliest organisms
THE DOMAINS OF LIFE A newer system recognizes two basically distinctive groups of prokaryotes The domain Eubacteria (Making a six kingdom system) The domain Archaea A third domain, the Eukarya, includes all kingdoms of eukaryotes BACTERIA ARCHAEA EUKARYA Earliest organisms
Bacteria & Archaebacteria Eukaryote Classification Prokaryote 6 Kingdom system Prokaryotes No separate organelles in their cells Bacteria Archaebacteria Eukaryotes Separate organelles in their cells Protists Plants Fungi Animals Bacteria & Archaebacteria
Kingdom Archaebacteria Prokaryotes Kingdom Protist Kingdom Fungi Kingdom Plant Kingdom Animal Kingdom Archaebacteria Kingdom Bacteria Eukaryotes
Kingdoms Based on the following criteria: 1. Presence or absence of a nuclear membrane 2. unicellular or multicellular 3. Type of nutrition
Bacteria and Archaea more modern divided into Bacteria & Archaea (inhabit extreme environments) (6 kingdom ) Prokaryotes Most primitive most are Unicellular Asexual Many have a cell wall
Protista Eukaryotic Moist environments Mostly unicellular Most diversity Most nutritionally diverse
Protista
Protista
Fungi Eukaryotes mostly Multicellular Asexual and sexual-spores Heterotrophic -absorption
Fungi
Plantae Eukaryotes Multicellualr Sexual/asexual Autotrophic
Plantae
Animalia Eukaryotes Multicellular Sexual/asexual Heterotrophic- ingestion
Animalia