Classification Notes

Transcription

1 Name Living Environment Classification Notes Characteristics of Living Things All living things have a cellular organization, contain similar chemicals, use energy, grow and develop, respond to their surroundings, and reproduce. Cellular Organization All organisms are made of cells. Cell the basic unit and structure of an organism Unicellular single celled (one cell) Example bacteria Multicellular organisms composed of many cells Example humans The Chemicals of Life The cells of all living things are composed of chemicals. Chemicals found in cells: Carbohydrates, proteins, lipids, nucleic acids Energy Use The cells of organisms use energy to do what living things must do, such as grow and repair injured parts. Growth and Development Growth the process of becoming larger Development the process of change that occurs during an organism s life to produce a more complex organism Response to Surroundings Stimulus a change in the surroundings that cause an organism to react Response an action or change in behavior Why do living things need to react to their surroundings? to escape predators etc. Reproduction Reproduce produce offspring similar to the parent What would happen if living things did not reproduce? they would be extinct What are some types of reproduction? Sexual 2 parents Asexual 1 parent

2 Classification the process of grouping things based on their similarities Why do scientists need to classify things? Easier to study Group things for medical reasons Early Classification Systems The first scientist to develop a classification system for organisms was Aristotle (a Greek scholar). He divided animals into three groups: those that fly, those that swim, and those that walk crawl or run. Aristotle used observations to classify organisms. In the 1750s, a Swedish scientist named Carolus Linnaeus expanded on Aristotle s ideas of classification. Linnaeus also used his observations to devise a naming system for organisms. He developed a system of grouping organisms using an organism s morphology to categorize them. Morphology form and structure Taxonomy names and groups of organisms according to their characteristics and evolutionary history Binomial nomenclature the naming system for organisms in which each organism is given a two-part name (genus & species) Genus a classification grouping that contains similar, closely related organisms. Example Ursus - bears Species a group of similar organisms that can mate and produce fertile offspring How is your name similar to Linnaeus s binomial nomenclature system? You have 2 names First and Last Linnaeus s system Genus and Species

3 Clade an evolutionary branch of a cladogram that includes a single ancestor and all its descendants Cladogram a diagram showing patterns of shared characteristics among species A cladogram links groups of organisms by showing how evolutionary lines branched off from common ancestors. The goal of evolutionary classification is to group species into larger categories that show lines of evolutionary descent. This is in contrast to showing only their similarities and differences. Levels of Classification King Phillip Came Over For Great Spaghetti Modern biologists classify organisms into seven levels. The levels are based on the organisms shared characteristics and on common ancestors. First an organism is placed in a broad group, which is then divided into more specific groups.

4 The seven levels of classification: Kingdom Broad Phylum Class Order Family Genus Species Specific Classification and Evolution Today s system of classification considers the history of a species when classifying the species. Species with similar evolutionary histories are classified more closely together. How can scientists gather information about the evolutionary history of a species? Fossils, DNA, similar features

5 Today scientists use a six kingdom classification system to classify organisms. The six kingdoms are Eubacteria, Archeabacteria, Protista, Fungi, Plantae, and Animalia.