Classification 2003 video

Information about Classification 2003 video

Published on August 4, 2014

Author: nitin240jain

Source: authorstream.com

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PowerPoint Presentation: Classification of Living Organisms Taxonomy: Taxonomy In science, the practice of classifying organisms is called taxonomy (Taxis means arrangement and nomos means method). The modern taxonomic system was developed by the Swedish botanist Carolus (Carl) Linneaeus (1707-1788). He used simple physical characteristics of organisms to identify and differentiate between different species, and is based around genetics. PowerPoint Presentation: Linneaeus developed a hierarchy of groups for taxonomy. To distinguish different levels of similarity, each classifying group, called  taxon   is subdivided into other groups. To remember the order, it is helpful to use a mnemonic device. The taxa in hierarchical order: Domain - Archea , Eubacteria , Eukaryote Kingdom - Plants, Animal, Fungi, Protists Phylum Class Order Family Genus Species PowerPoint Presentation: The domain is the broadest category, while species is the most specific category available. The taxon Domain was only introduced in 1990 by Carl Woese, as scientists reorganise things based on new discoveries and information. For example, the European Hare would be classified as follows: Eukaryote --> Animal --> Chordata --> Mammalia --> Lagomorpha --> Leporidae --> Lepus -->  Lepus europaeus . Binomial nomenclature: Binomial nomenclature Binomial nomenclature  is used to name an organism, where the first word beginning with a capital is the genus of the organism and the second word beginning with lower-case letter is the species of the organism. The name must be in italics and in Latin, which was the major language of arts and sciences in the 18th century. The scientific name can be also abbreviated, where the genus is shortened to only its first letter followed by a period. In our example,  Lepus europaeus  would become  L. europaeus'. PowerPoint Presentation: Taxonomy and binomial nomenclature are both specific methods of classifying an organism. They help to eliminate problems, such as mistaken identity and false assumptions, caused by common names. An example of the former is the fact that a North American robin is quite different from the English robin. An example of the latter is the comparison between crayfish and catfish, where one might believe that they both are fish when in fact, they are quite different. PowerPoint Presentation: Nomenclature is concerned with the assignment of names to taxonomic groups in agreement with published rules. To study for a test these are the best words to know taxonomist, biologist, chemist, geologist, unicellular, multi- cellular, bilateral symmetry, radial symmetry, chlorophyll, photosynthesis, respiration, reproduction, vertebrates, endoskeleton, exoskeleton, consumers, decomposers, heterotroph , autotroph , vascular, non-vascular. these are all part of classifying things. Eukaryotes & Prokaryotes : Eukaryotes & Prokaryotes Eukaryotes : Eukaryotes PowerPoint Presentation: A  eukaryote  is any organism whose cells contain a nucleus and other structures (organelles) enclosed within membranes. Eukaryotes are formally the  taxon   Eukarya  or  Eukaryota . Eukaryotes are more complex in structure, with nuclei and membrane-bound organelles. Some characteristics of eukaryotes are: Large (100 - 1000 μ m) DNA in nucleus, bounded by membrane Genome consists of several chromosomes. Sexual reproduction common, by mitosis and meiosis Mitochondria and other organelles present Most forms are multicellular Aerobic Prokaryotes: Prokaryotes PowerPoint Presentation: The  prokaryotes  are a group of organisms whose cells lack a membrane-bound nucleus (karyon). Prokaryotes refer to the smallest and simplest type of cells, without a true nucleus and no membrane-bound organelles. Bacteria fall under this category. Some characteristics: Small (1-10 μm) DNA circular, unbounded Genome consists of single chromosome. Asexual reproduction common, not by mitosis or meiosis. No general organelles Most forms are singular Anaerobic The Three Domains : The Three Domains The three domains are organised based on the difference between eukaryotes and prokaryotes. Today's living prokaryotes are extremely diverse and different from eukaryotes. This fact has been proven by molecular biological studies (e.g. of RNA structure) with modern technology. The three domains are as follows: Archea (Archeabacteria): Archea ( Archeabacteria ) Archea  consists of archeabacteria, bacteria which live in extreme environments. The kingdom Archaea belongs to this domain. Eubacteria: Eubacteria Eubacteria  consists of more typical bacteria found in everyday life. The kingdom Eubacteria belongs to this domain. Eukaryote: Eukaryote Eukaryote  encompasses most of the world's visible living things. The kingdoms Protista , Fungi, Plantae , and Animalia fall under this category. The Six Kingdoms : The Six Kingdoms Under the three domains are six kingdoms in taxonomy. The first two,  Plants  and  Animals , are commonly understood and will not be expounded here. Protista: Protista Protista , the third kingdom, was introduced by the German biologist Ernst Haeckel in 1866 to classify micro-organisms which are neither animals nor plants. Since protists are quite irregular, this kingdom is the least understood and the genetic similarities between organisms in this kingdom are largely unknown. For example, some protists can exhibit properties of both animals and plants. Fungi: Fungi Fungi  are organisms which obtain food by absorbing materials in their bodies. Mushrooms and moulds belong in this kingdom. Originally, they were part of the plant kingdom but were recategorised when they were discovered not to photosynthesis. Eubacteria: Eubacteria Eubacteria  are bacteria, made up of small cells, which differ in appearance from the organisms in the above kingdoms. They lack a nucleus and cell organelles. They have cell walls made of peptidoglycan . Archae: Archae Archae (or Archaebacteria )  are bacteria which live in extreme environments, such as salt lakes or hot, acidic springs. These bacteria are in their own category as detailed studies have shown that they have unique properties and features (ex. unusual lipids that are not found in any other organism)which differ them from other bacteria and which allow them to live where they live. Their cell walls lack peptidoglycan . PowerPoint Presentation: Thank You A Presentation By: Nitin Jain

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