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Classification Go to Section: _________________ ______ _________________ ______ _________________ ______ Supermarkets The Challenge • Biologists have identified and named approximately 1.5 million species so far. • They estimate that between 2 and 100 million species have yet to be identified. Finding Order in Diversity • 1. Why Classify? – To study the diversity of life – To organize and name organisms 2. Why give scientific names? – Common names are misleading • jellyfish Go to Section: silverfish None of these animals are fish! star fish Why Scientists Assign Scientific Names to Organisms Some organisms have several common names This cat is commonly known as: •Florida panther •Mountain lion •Puma •Cougar Scientific name: Felis concolor Scientific name means “coat of one color” Go to Section: Origin of Scientific Names • By the 18th century, scientists realized that naming organisms with common names was confusing. • Scientists during this time agreed to use a single name for each species. • They used Latin and Greek languages for scientific names. Slide # 6 Linnaeus: The Father of Modern Taxonomy 1732: Carolus Linnaeus developed system of classification – binomial nomenclature a. Two name naming system b. Gave organisms 2 names Genus (noun) and species (adjective) Rules for naming organisms 1. Written is Latin (unchanging) 2. Genus capitalized, species lowercase 3. Both names are italicized or underlined EX: Homo sapiens: wise / thinking man Go to Section: Carolus Linnaeus Linnaeus’s System of Hierarchy Least specific Kingdom 1. Phylum Class 2. a. Family c. Class b. Species d. Order Order Based on their names, you know that the baboons Papio annubis and Papio cynocephalus do not belong to the same: Family a. Family c. Order b. Genus d. Species Genus Most specific Species Go to Section: Which of the following contains all of the others? SPECIES Binomial Nomenclature Example • For example, the polar bear is named Ursus maritimus. • The genus, Ursus, describes a group of closely related bear species. • In this example, the species, maritimus, describes where the polar bear lives—on pack ice floating on the sea. Modern Classification • Linnaeus grouped species into larger taxa, such as genus and family, based on visible similarities. • Darwin’s ideas about descent with modification evolved into the study of phylogeny, or evolutionary relationships among organisms. Modern Classification • Modern biologists group organisms into categories representing lines of evolutionary descent. • Species within a genus are more closely related to each other than to species in another genus. Genus: Felis Genus: Canis Similarities in DNA and RNA • Scientists use similarities and differences in DNA to determine classification and evolutionary relationships. • They can sequence or “read” the information coded in DNA to compare organisms. Kingdoms and Domains • In the 18th century, Linnaeus originally proposed two kingdoms: Animalia and Plantae. • By the 1950s, scientists expanded the kingdom system to include five kingdoms. The Five Kingdom System Monera bacteria Protista Amoeba, slime mold Fungi Plantae Animalia mushrooms, yeasts, molds flowering plants, mosses, ferns, cone-bearing plants mammals, birds, insects, fishes, worms, sponges The Six Kingdom System • In recent years, biologists have recognized that the Monera are composed of two distinct groups. • As a result, the kingdom Monera has now been separated into two kingdoms: Eubacteria and Archaebacteria, resulting in a sixkingdom system of classification. The Three-Domain System • Scientists can group modern organisms by comparing ribosomal RNA to determine how long they have been evolving independently. • This type of molecular analysis has resulted in a new taxonomic category—the domain. The Three Domains • The three domains, which are larger than the kingdoms, are the following: • Eukarya – protists, fungi, plants and animals • Bacteria – which corresponds to the kingdom Eubacteria. • Archaea – which corresponds to the kingdom Archaebacteria. Classification of Living Things The three-domain system Bacteria Archaea Eukarya The six-kingdom system Eubacteria ArchaeProtista Plantae Fungi bacteria Animalia Hierarchical Ordering of Classification As we move from the kingdom level to the species level, more and more members are removed. Each level is more specific. Go to Section: ARCHAE BACTERI A EUBACTE RIA PROTIST FUNGUS PLANT ANIMAL Number of Cells (single/multi) Single Single Single (except algae) Multi (except yeast) Multi Multi Prokaryotic/ Eukaryotic Prokaryotic Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic Producer/ Consumer Both Both Both Consumer (decompos er) Producer Consumer Mobile/Non-mobile Both Both Both Nonmobile Nonmobile Mobile Cell Wall (yes/no) Sometimes Sometimes No Yes (Chitin) Yes (Cellulose) No Answer the questions using this chart: A B C D E KINGD OM Animailia Animalia Animailia Animalia Animailia PHYLU M Chordata Chordata Chordata Chordata Chordata CLASS Mammalia Mammailia Mammalia Mammailia Reptilia ORDER Carnivora Cetacea Cetacea Eusuchia Carnivora FAMILY Canidae Dolphinida Hyaenidae e Dolphinidae Cercapithecida e GENUS Tursiops Hyaena Orcinus Crocodylus aduncus brunnea orca acutus Lycaun SPECIES pictus Kingdom Archaebacteria Cell Type Prokaryote Number of Cells Nutrition Unicellular Location Extreme Environments Volcanoes, Deep Sea Vents, Yellowstone Hot Springs Sometimes Cell Wall Examples Go to Section: Autotroph or Heterotroph Methanogens Thermophiles Kingdom Archaebacteria • Archaebacteria: – Some scientists believe that archaebacteria are the oldest living organisms. – They live in extreme environments such as sulphur springs, deep-sea volcanic vents, the great salt lake, intestines of mammals, and the reactors in nuclear power plants. – Can be autotrophs (live near cracks in the ocean floor) Kingdom Eubacteria Cell Type Number of Cells Nutrition Prokaryote Unicellular Autotroph or Heterotroph Location Everywhere! Cell Wall Sometimes Examples Streptococcus, Escherichia coli (E. coli) Go to Section: E. coli Streptococcus Kingdom Eubacteria • Eubacteria: – These are the bacteria that we are more familiar with. – They are classified according to their shape and their reaction to Gram staining. Kingdom Eubacteria • Some bacteria are heterotrophs. – They must rely on other organisms as a food source. – Parasitic- get the nutrients they need by feeding on living organisms. – Saprotrophs- feed on dead organisms and organic wastes. Kingdom Eubacteria • Some bacteria are autotrophs. – Photosynthetic autotrophs- contain chlorophyll and live in habitats where they get enough light to go through photosynthesis. – Chemosynthetic autotrophs- can also make organic molecules for food, but they do so by breaking down inorganic compounds that contain nitrogen and sulfur. Kingdom Protista Cell Type Eukaryote Number of Cells Most Unicellular, some multicellular Nutrition Autotroph or Heterotroph Sometimes Cell Wall Examples Amoeba, Paramecium, Euglena, The “Junk-Drawer” Kingdom Go to Section: Paramecium Green algae Amoeba Kingdom Protista • Kingdom Protista is called the catch all kingdom because it contains so many organisms that don’t fit into other kingdoms. • They can be unicellular or multicellular; microscopic or large; autotrophs or heterotrophs. • All protists are eukaryotes. Kingdom Protista • Pseudopods- used by some protists for movement Kingdom Protista • Contractile vacuolewhen water enters the protist, the contractile vacuole contracts and pushes the water back out. – Used by protists that live in hypotonic environments to keep them from swelling and bursting. Kingdom Protista • Animal-like protists: – Called protozoans – Single celled – Ex.- amoeba, which moves by using pseudopods and doesn’t have a cell wall – Other protozoans move by cilia or flagella – Can cause diseases such as malaria Kindom Protista • Plant-like protists: – Algae- carry out photosynthesis, but do not have roots, stems, leaves, or flowers like plants. • Some algae contain other color pigments and appear red, brown, or golden. • Can be unicellular or multicellular and meters long – Diatoms- unicellular protists that have a glasslike outer shell. Kingdom Protista • Fungus-like protists: – Decompose dead organisms – Able to move from place to place for part of their life cycle (true fungi cannot) – Include slime-molds, downy mildews, and water molds. – Very colorful Kingdom Fungi Cell Type Eukaryote Number of Cells Most multicelluar, some unicelluar Nutrition Heterotroph Cell Wall Made of Chitin Example Mushroom, yeast, mildew, mold Most Fungi are DECOMPOSERS Go to Section: Mushroom Kingdom Fungi • Can grow anywhere there is moisture • Do not contain chlorophyll (this is why they are not considered plants!) • Are heterotrophs • Fungus get their food by extracellular digestion – They send out hyphae into their food source. These hyphae release enzymes that break down the food into molecules that can be absorbed directly by the hyphae. Kingdom Fungi • Have cell walls made of chitin • Some are saprophytes – Mushrooms – Feed on dead organic matter • Lichens- a mutualistic relationship between a fungus and a green alga living close together. – Lichens help break down rocks into soil so that plants can grow. Kindom Fungi • Fungi can reproduce sexually, asexually, or both. – Yeasts reproduce asexually by budding or by fission. – Mushrooms reproduce sexually by forming spores (haploid) that must germinate and fuse to produce a new mushroom. – Bread molds and other fungi can reproduce sexually when conditions are right, or by asexual spores. Kingdom Plantae Cell Type Eukaryote Number of Cells Multicellular Nutrition Autotroph Cell Wall Made of cellulose Mosses, ferns, conifers, flowering plants Examples Mosses growing on trees Go to Section: Ferns : seedless vascular Douglas fir: seeds in cones Sunflowers: seeds in flowers Kingdom Animalia Cell Type Eukaryote Number of Cells Multicellular Nutrition Heterotroph Cell Wall Examples None Sponges, worms, insects, fish, mammals Bumble bee Sage grouse Jellyfish Hydra Poison dart frog Sponge Go to Section: Cladogram • An evolutionary tree that suggests how species may be related • Over evolutionary time, certain traits in a group of species, or clade, stay the same. Other traits change. Derived Characters • Derived characters are traits that are shared by some species but not by others • The more closely related species are, the more derived characters they will share • Derived characters are shown as hash marks Nodes • Each place where a branch splits is called a node. • Nodes represent the most recent common ancestor shared by a clade. What do the house cat and the turtle have in common? What does the leopard have in common with the wolf? What organisms are most closely related?