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Chapters 28 30

Chapters 28 30






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    Chapters 28 30 Chapters 28 30 Presentation Transcript

    • Chapters 28-30: Diversity of Life
      • Taxonomic Classification
      2. Viruses and Prokaryotes 3. Protists and Fungi 4. Plants 5. Animals
    • 1. Taxonomic Classification
    • The Classification of Organisms There are ~1.5 million known species on our planet.
      • total # or species on earth estimated to be
      • anywhere from 7 to 100 million
      To study so many organisms and their evolutionary relationships requires:
      • standard nomenclature
      • same name used worldwide for a given organism
      • hierarchy, system of classification
      • allows organization by “relatedness”
      • By classifying organisms into groups( “taxa”), it help us to answer such questions as:
      • Is a snake more closely related to a worm or a lizard?
      • Is a mushroom more related to a plant or a mold?
      • All organisms are separated into 4 major groups (Kingdoms), which are further sub-divided into smaller and smaller groupings
    • The Taxonomic Hierarchy Each level of the hierarchy is referred to as a taxa : D omain K ingdom P hylum C lass O rder F amily G enus S pecies Humans eukarya animal chordates mammals primates hominids Homo sapiens K ing P hilip C an O nly F ind G reen S ocks
    • Each organisms is named using both its genus and species . A species is defined as a group of organisms that interbreed with one another to produce fertile offspring. Example: horse: Equus caballus donkey: Equus asinus Same genus, different species. Their offspring, the mule, is sterile. worm: Craniella abracadabra beetle: Agra katewinsletae lichen: Caloplaca obamae Wasp: Polemistus chewbacca
    • The Major “Taxa” The 3 Domains : 4 Kingdoms of Eukarya: Bacteria Archaea Eukarya Protists, Fungi, Plants & Animals
    • Bacteria:
      • “ common” prokaryotes
      Archaea (or archaebacteria):
      • “ unusual” prokaryotes or “extremophiles”
      • thrive in harsh environments (acid, high salt, boiling…)
      • all organisms made of eukaryotic cells
      Protists: single-celled eukaryotes Fungi: multicellular; absorb food Plants: multicellular; photosynthesize Animals: multicellular; ingest food
    • 2. Viruses and Prokaryotes
    • euk. cell bacteria Viruses are Small, Simple, Non-living Consist of genetic material ( DNA or RNA ) inside a protein coat (may have a membrane envelope ).
      • no metabolic
      • capabilities
      • reproduce only
      • within a host
      • frequently “lyse”
      • or kill host cell
    • Viruses come in Immense Variety Differ in:
      • size & shape
      • genetic
      • material
      • mode of
      • infection
      • host
      • specificity
      • DNA, RNA,
      • double or
      • single strand
    • AIDS Virus Infection The AIDS virus is a retrovirus: must convert RNA to DNA
    • Types of Prokaryotes Prokaryotes = single-celled organisms lacking nuclei and other organelles Bacteria
      • live in every conceivable environment
      • immense variety of metabolism, physiology
      • play many essential biological roles
      • nitrogen fixation (all plants depend on it!)
      • decomposition (essential for recycling of nutrients)
      • digestion (gut flora in humans, cattle,…)
      • thrive in very extreme environments
    • Prokaryotes come in 3 Basic Shapes spherical (coccus) rod-shaped (bacillus) corkscrew-shaped (spirillum)
    • Extreme Habitats
    • 3. Protists and Fungi
    • Types of Protists Protists = most single-celled eukaryotic organisms
      • some can form multicellular aggregates
      • e.g., trypanosomes,
      • plasmodium (causes malaria)
      1) Protozoa ( “first animals”)
      • heterotrophs (ingest food)
      • amoebae, paramecia,
      • zooplankton, trypanosomes
      • many are parasites
      • 2 basic types of protist:
    • zygote sporozoite gametocytes Sexual phase in mosquito female gamete male gamete food canal salivary gland 1. In the gut of a female Anopheles mosquito, gametes fuse, and the zygote undergoes many divisions to produce sporozoites, which migrate to her salivary gland. 2. When the mosquito bites a human, the sporozoites pass from the mosquito salivary glands into the bloodstream and then the liver of the host. liver cell 3. Asexual spores (merozoites) produced in liver cells enter the bloodstream and then the red blood cells. A sexual phase in humans 5. Merozoites and toxins pour into the bloodstream when the red blood cells rupture, causing chills and fever. 4. When the red blood cells rupture, merozoites invade and reproduce asexually inside new red blood cells. 6. Some merozoites become gametocytes, which enter the blood- stream. If taken up by a mosquito, they become gametes. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. MALARIA
    • 2) Algae ( “ photosynthetic protists”)
      • phytoplankton
      • “ seaweeds”
      (dinoflagellates, diatoms, volvox) volvox seaweed (kelp) diatoms
    • The Fungi Types of Fungi include:
      • molds
      • yeast
      • mushrooms
    • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. fertilization zygospore meiosis Sexual Asexual sporangium mycelium + strain – strain © Runk/Schoenberger/Grant Heilman Photography
    • Key Characteristics of Fungi Fungi digest organic material externally (they don ’t ingest food like animals do):
      • secrete digestive enzymes, absorb food
      • some are detritus feeders (consume dead
      • matter) some are parasites (prey on living)
      • decomposition of dead organic matter is extremely
      • important for ecosystems (recycles nutrients)
      Fungal cells have cell walls (made of chitin ) Can reproduce sexually or asexually
    • 4. Plants
    • What constitutes a Plant? Major plant phyla, classes Plants are multicellular, photosynthetic, and share characteristic modes of reproduction
    • The Bryophytes Liverworts Key features: Mosses
      • lack true leaves, roots,
      • stems
      • no internal vasculature
      • rely mainly on diffusion
      • limits their size
        • Can live on bare rock, fences, cracks of sidewalks
          • Selective advantage to being small and simple
        • Help convert rocks to soil
        • Peat moss
          • Used as fuel
          • Holds water
          • Used in gardens to improve soil
      Adaptations and Uses of Nonvascular Plants
    • The Tracheophytes Tracheophytes are the vascular plants :
      • contain vessels to transport material internally
      There are 3 basic types of vascular plant:
      • seedless vascular plants (e.g., ferns, horsetails)
      • gymnosperms (all “cone-bearing” plants)
      • angiosperms (all flowering plants)
    • Seedless Vascular Plants Horsetails Ferns
      • most primitive
      • vascular plant
    • Seedless Vascular Plants
      • Vascular tissue
        • Xylem conducts water and minerals
        • Phloem transports organic nutrients
      • Have true roots, stems, and leaves
      • Seedless vascular plants produce windblown spores (not seeds)
    • Seed Plants Gymnosperms and Angiosperms
        • Most plentiful plants in the biosphere today
        • Seeds contain a sporophyte embryo and stored food within a protective coat
          • Allows an embryo to survive during long periods of dormancy
    • Gymnosperms
      • conifers (pines, firs, etc…) ,
      • cycads, gingko
      • seeds
      • produced
      • in cones
      • (not flowers)
      All “cone-bearing” plants: pine cycad gingko juniper
    • Conifers
        • Pine, spruce, fir, cedar, hemlock, redwood, and cypress
        • Adapted to cold, dry weather
        • Needlelike leaves conserve water with thick cuticle and recessed stomata
        • Dominant sporophyte produces pollen cones and seed cones
        • Wood is used in construction and for making paper
    • Angiosperms All flowering plants:
      • most dominant type of plant
      * seeds are plant embryos + nutrients within a seed coat
      • produce seeds* in flowers (via fertilization of gametes)
      • disperse seeds via fruits
    • Flower Diversity
    • Seed Plants
      • Life cycle
        • Sexual reproduction in flowering plants is dependent on the flower
          • Produces both pollen and seeds
        • Pollination can be by wind or pollinator
          • Bees, wasps, flies, butterflies, moths, beetles, and even bats
          • Many flowers are adapted to attract quite specific pollinators
        • Fruits
          • Final product of a flower
          • Aids in the dispersal of seeds
    • 5. Animals Invertebrates Vertebrates
    • Characteristics of Animals All members of the Animal Kingdom:
      • consume food derived from other organisms
      • feed by “ingesting” food
      • unlike fungi which “absorb” food externally
      • consist of eukaryotic cells w/o cell walls
      • are heterotrophs
      • are multicellular
      Most members of the Animal Kingdom:
      • have a symmetrical body plan
      • radial or bilateral symmetry
      • have distinct tissues, organs
      • reproduce sexually
    • Animal Diversity
    • Radial vs Bilateral Symmetry Radial Symmetry
      • symmetrical halves “no matter how you slice it”
      Bilateral Symmetry
      • only one plane of
      • symmetry
      bilateral symmetry anterior posterior dorsal ventral
    • Vertebrate vs Invertebrate Vertebrate animals
      • have a backbone or “vertebral” column
      • less than 3% of known animal species
      Invertebrate animals
      • NO backbone or “vertebral” column
      • > 97% of known animal species
      • any “non-vertebrate” animal
      The vertebrate/invertebrate distinction is somewhat “old school” They more or less constitute “sub-kingdoms”
    • Invertebrates
    • Major Invertebrate Phyla “ Lower” Invertebrates Porifera
      • all sponges
      • anemones, coral, jellyfish
      • all “flatworms”
      • all “roundworms”
      “ Higher” Invertebrates Annelids
      • all “segmented worms”
      • snails, clams, squids
      • insects, spiders, crabs
      • starfish, sea urchins
    • The Porifera (Sponges) The simplest, most primitive animal phylum
      • lack distinct tissues or organs
      • some reproduce asexually (no union of sperm & egg)
      • don ’t necessarily display bodily symmetry
      • are sessile (i.e., fixed in placed, “non-motile”)
    • Simple Sponge Anatomy Filter feeder Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b. Sponge organization c. d. sponge wall pore spicule amoebocyte collar cell (choanocyte) nucleus collar flagellum amoebocyte osculum H 2 O in through pores H 2 O out central cavity epidermal cell a. Yellow tube spoge,Aplysina fistularis a: © Andrew J. Martinez/Photo Researchers, Inc
    • The Cnidarians Anemones, jellyfish, corals…
      • have radial symmetry
      • are sessile, or free-
      • floating
      • All aquatic
      • only 2 embryonic germ layers
      • endoderm
      • (inner layer)
      • ectoderm
      • (outer layer)
      Mouth and anus
    • Cnidarian Diversity Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b. Sea anemone, Corynactis c. Cup coral, Tubastrea e. Jellyfish, Aurelia d. Portuguese man-of-war, Physalia b: © Azure Computer & Photo Services/Animals Animals; c: © Ron & Valerie Taylor/Bruce Coleman, Inc. ; d: © Runk/Schoenberger/Grant Heilman Photography; e: © © Amos Nachoum/Corbis
    • The Platyhelminthes (Flatworms)
      • bilateral symmetry
      • have internal organs
      • lack respiratory,
      • circulatory systems
      • many are parasites
      “ Planaria” “ Tapeworms”
    • The Nematodes (Roundworms)
      • estimated 500,000
      • different species
      • small in size, frequently
      • parasitic
      • important decomposers
      fresh water nematode Trichinella “ heartworms”
    • What some roundworms can do to you
        • Trichinosis
          • Caused by Trichinella spiralis
          • Humans contract the worm by eating undercooked pork
          • Larvae migrate out of intestines and form painful cysts in the muscles
        • Elephantiasis
          • Caused by a filarial worm
          • Migrates into lymphatic vessels and prevents lymph drainage
          • Swelling of limbs occurs
        • Pinworms and hookworms
          • Roundworm parasites which cause problems in children
    • Annelids (Segmented Worms) Earthworms, leeches, sandworms…
      • repetitive
      • body segments
      • closed circula-
      • tory system*
      • digestive tract
      • with 2 openings
      • (mouth, anus)*
        • Gas exchange is across the body wall
    • The Mollusks Grouped into 3 main classes: GASTROPODS (snails & slugs) BIVALVES (clams, scallops, oysters) CEPHALOPODS (squid, octopus, cuttlefish) snail scallop
    • octopus squid nautilus Cephalopods:
      • most advanced
      • mollusks
      • unusually high
      • intelligence
      http://www.youtube.com/watch?v=jN99Kx_ghC8 http://www.youtube.com/watch?v=p9A-oxUMAy8
    • The Arthropods 3 main classes of Arthropod: INSECTS
      • estimated
      • 9 million
      • species!
      • spiders, ticks
      • scorpions,
      • mites
      • crabs, shrimp
      • lobsters,
      • barnacles
    • Characteristic Arthropod Features Have an exoskeleton (external skeleton)
      • must “molt” for growth to occur
      Segmented bodies Open circula- tory systems
      • e.g., moths, butterflies
      Many undergo metamorphosis
    • The Echinoderms Starfish, sea urchins, sea cucumbers…
      • calcium carbonate
      • endoskeleton
      • radial symmetry (adult)
      • larvae are bilateral
    • Vertebrates
    • The Phylum Chordata Main characteristics of the Chordates :
      • have a notochord
      • usu. gives rise to the backbone during development
      • have a hollow nerve cord
      • becomes brain & spinal cord during development
      • pharyngeal “gill slits”
      • may disappear during development
      • have a tail
      • may disappear during development
      ***All vertebrates are chordates but not all chordates are vertebrates***
    • Major Chordate Classes Agnatha
      • “ jawless” fishes
      • cartilagenous fishes
      • bony fishes
      • frogs, salamanders…
      • lizards, snakes, turtles…
      Birds (Aves)
      • chickens, eagles…
      • humans, cats, dogs…
    • Agnatha Jawless fishes:
      • hagfish
      • lamprey
    • Chondrichthyes Sharks, rays and skates
      • skeleton made of cartilage* (no bone)
      • have jaws*
    • Osteoichthyes All bony fishes (have true bone*)
      • most diverse class of vertebrates
      • have scales*
      • air bladder* (precursor to lungs?)
    • Amphibians
      • need water to reproduce
      • breathe through skin &
      • lungs*
      • 1 st vertebrates to leave
      • the water
    • Reptiles
      • water-proof skin*
      • first organisms to develop in an amniotic egg*
      • can develop away from water
      • first true “land” vertebrates
      • A water-impermeable structure which contain a fluid and so the embryo to develop on land without danger of desiccation.
      • It also contain a yolk to nourish the developing organism.
      • Amniotic eggs protect the developing organism, as well as aid in gas and energy exchange.
      What is an amniotic egg?
    • YOLK: sacs that contains the nutrients CHORION: encloses all the other sacs ALLANTOIS: sac that stores the metabolic wastes AMNION: A fluid-filled sac that provides an aquatic environment to the developing embryo/ Amniotic egg structure
    • Birds (Aves)
      • thought to have evolved from reptiles
      • wings & feathers*
      • first homeothermic organisms*
      • maintain constant body temperature (warm-blooded)
      • amniotic egg
    • Mammals
      • most have placenta*
      • young develop internally
      • mammary glands*
      • homeothermic
      • hair*
      • nourish young with milk