Transcript Slide 1
Classification • Taxonomy naming system for the organization of life. – Grouping or categorizing based on similarities Modern classification began with the work of Carolus Linnaeus, who grouped species according to shared physical characteristics. In the life sciences, binomial nomenclature is the formal method of naming species. As the word "binomial" suggests, the scientific name of a species is formed by the combination of two terms: the genus name and the species descriptor. Classification of living systems • • • • • • • Kingdoms Phylum Class Order Family Genus Species Classification • • • • • • • 6 KINGDOMS Animalia Plantae Fungi Protista Prokaryotes Eukaryotes } Used to be 1 kingdom- Monera (Bacteria only) • Viruses are not classified as living. Viruses do however demonstrate reproductive capabilities like living things. They are smaller than bacterial cells! The 6 kingdoms • Prokaryotes (Used to be 1 kingdom, Monera) – Archaebacteria – Eubacteria • Eukaryotes – Fungi – Protista – Animal – Plantae unicellular prokaryotes (no nucleus or membrane-bound organelles) complex and have a nucleus and membrane-bound organelles Overview of the 6 kingdoms • Archaebacteria – Unicellular – Live in extreme environments – Prokaryotic Overview of the 6 kingdoms • Eubacteria - Unicellular - Prokaryotic -“Common bacteria” Overview of the 6 kingdoms • Protista – Eukaryotic – Unicellular or colonial – Lots of different life styles • Fungi – Cell walls made of chitin – Eukaryotic – Multicellular – External heterotrophs Plantae •Multicellular •Autotrophic •Absorb sunlight to make glucose – Photosynthesis •Cell walls made of cellulose 9 Animalia • Multicellular • Ingestive heterotrophs (consume food & digest it inside their bodies) • Feed on plants or animals 10 Overview of the 6 kingdoms • Plantae – Eukaryotic & Multicellular – Cell walls made of cellulose – Autotrophic • Animalia – Eukaryotic & Multicellular – No cell walls – Internal heterotrophs copyright cmassengale 12 •Let’s look at an example of taxonomy in action! What is my name? Puma ? What is my name? Devil Cat ? Ghost Cat ? What is my name? My real name is Puma concolor What is my name? Binomial Nomenclature • There are at least 50 common names for Puma concolor. • Common names vary according to region, country or language. • Soooo……why use a scientific name? Binomial Nomenclature Two name system for writing scientific names. •The genus name is written first (always Capitalized). •The species name is written second (never capitalized). •Both words are italicized if typed or underlined if hand written. The name is also in Latin (a dead language). Binomial Nomenclature • More examplesGenus and species Common name Range Panthera leo Lion Africa (Asia) Panthera onca Jaguar N. & S. America Panthera pardus Leopard Africa, Asia, Europe Panthera tigris Tiger Asia How many organisms are out there? • Scientists currently estimate that – There are 10 million species worldwide – Over 5 million live in the tropics – Most unnamed species are small or microscopic Why is taxonomy useful? • Helps prevent confusion among scientists • Helps to show how organisms are related • Can be used to reconstruct phylogenies – evolutionary histories – of an organism or group Organization of LIFE • • • • • • CELL – BASIC UNIT OF LIFE TISSUE- MANY CELLS ORGANS- MANY TISSUES ORGAN SYSTEMS-GROUPED ORGANS ORGANISMS – CONTAINS ORGAN GROUPS SPECIES- GROUPS OF THE SAME ORGANISM Basis for Modern Taxonomy • Homologous structures (same structure, different function) • Similar embryo development • Molecular Similarity in DNA, RNA, or amino acid sequence of Proteins copyright cmassengale 24 Homologous Structures (BONES in the FORELIMBS) shows copyright cmassengale 25 Similarities in mammals. Similarities in Vertebrate Embryos copyright cmassengale 26 Cladogram • Diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales copyright cmassengale 27 Primate Cladogram copyright cmassengale 28 Dichotomous Keying • Used to identify organisms • Characteristics given in pairs • Read both characteristics and either go to another set of characteristics OR identify the organism copyright cmassengale 29 Example of Dichotomous Key •1a Tentacles present – Go to 2 •1b Tentacles absent – Go to 3 •2a Eight Tentacles – Octopus •2b More than 8 tentacles – 3 •3a Tentacles hang down – go to 4 •3b Tentacles upright–Sea Anemone •4a Balloon-shaped body–Jellyfish •4b Body NOT balloon-shaped - 5 copyright cmassengale 30