6-4 Notes Classifying Organisms
Chapter 6, Lesson 4 Historic Classification Systems
Aristotle, a Greek philosopher, was one of the first people to put organisms into categories. He categorized things as animals, plants, or minerals, and then according to where they livedair, land, or sea. Historic Classification Systems
In the mid-1700s, Swedish botanist, Linnaeus developed a classification system that grouped organisms by similar physical structures Historic Classification Systems
Linnaeuss system went from kingdom (most general)to species (most specific). Historic Classification Systems Historic Classification Systems
Members of a species group have the greatest number of traits in common and can breed and produce fertile offspring. Only species are subject to natural selection and evolve. Felis catus Historic Classification Systems
Linnaeus also developed a system for naming species that is still used. Each species has a two-word scientific name called its species name. The first word identifies its genus. Humans species name is Homo sapien. Historic Classification Systems
All small cats have Felis as the first word of their species name, because that is their genus. domestic cat Felis catus sand cat Felis margarita jungle cat Felis chaus wild cat Felis silvestris Historic Classification Systems
Basic features such as cell type, presence of a cell wall, or single-celled versus multicellular define each of the 6 kingdoms: Eubacteria Archaebacteria Protists Fungi Plantae Animalia Modern Methods of Classification
The modern study of classification, called systematics, uses DNA and molecular biology to identify related organisms. The more shared DNA sequences two species have, the more recent ancestor they probably share. Modern Methods of Classification
Scientists use haplotypes, samples of 1000 base pairs, to compare DNA sequences among organisms. DNA hybridization measures the percentages of DNA that are the same between two organisms. Modern Methods of Classification
Molecular biology led to a new highest level of classification called Domain, which is based on differences in a particular genetic sequence. There are 3 domains: Bacteria Archaea Eukarya Modern Methods of Classification Modern Methods of Classification
As more sophisticated techniques are developed, the classification system will continue to become more refined. Modern Methods of Classification
The current system of classification (from highest to lowest): Domain Kingdom Phylum Class Order Family Genus Species Cladograms Scientists create diagrams called cladograms to group organisms based on certain characteristics. A cladogram shows common ancestry, and helps scientists to better understand evolution. Cladograms Cladograms MYA Cladograms The National Museum of Natural History - Washington, D.C What was Linnaeus classification system based on?
6.4 Classifying Organisms What was Linnaeus classification system based on? Awhether things were plant, animal, or mineral Bwhere organisms livedair, water, or land Csimilar DNA sequences Dsimilar physical structures 6.4 Classifying Organisms
What approach measures the percentage of DNA that is similar between two organisms? ADNA hybridization BDNA sequencing Chaplotypes Dsystematics What is currently the highest level of classification?
Aanimalia Bdomain Ckingdom Dorder Which of the following does not provide independent evidence for the theory of evolution through natural selection? Afossil record Bcomparative anatomy Csystematics Dmolecular biology Which of the following is not a kingdom? A protista B fungi C eukarya
SCI 3. Which of the following is not a kingdom? Aprotista Bfungi Ceukarya Danimalia