Transcript PPT
Classification and the Kingdoms of Life Classification • There are 1.6 million types of plants and animals and 3-10 million organisms not identified • Need to organize information • Taxonomy – branch of biology that names and groups organisms according to their characteristics and evolutionary history Important People • Aristotle- classified based on qualities like shape, ability to do harm, whether they are air, land, or water dwellers • John Ray- defined species as organisms capable of interbreeding and producing fertile offspring. • Linnaeus- classified based on form and structure; came up with Binomial Nomenclature Binomial Nomenclature • Method of naming organisms by their genus and species. • Both genus and species are underlined or italicized. • Ex) Homo sapiens • Genus = Homo • Species = sapiens 7 levels of Classification • • • • • • • Kingdom Phylum Class Order Family Genus Species King Phillip Came Over From Great Spain Modern Taxonomy • Based on evidence such as the fossil record, morphology, embryology, development and DNA evidence. • Phylogenetic Tree-(see ex. on slide) • Cladogram -(see ex. on slide) • Dichotomous Key- instrument used to identify an organism based on certain characteristics (if…then.…) Phylogenetic Tree- shows evolutionary relationship between organisms Cladogram- use shared derived characters that evolved within the group being studied The Six Kingdoms of Life • Organisms in each kingdom are similar in their cellular structure, methods of obtaining nutrients, and metabolism. • Archabacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia. Bacteria • Prokaryotic, unicellular, auto or heterotrophic • Most have cell wall made up of peptidoglycan and have ribosomes • Autotrophs can get energy from sun (photosynthetic) or from inorganic substances (chemosyntheitic) • 2 types - Archeabacteria and Eubacteria Bacteria Reproduction • Binary fission (asexual) –chromosome of the bacteria replicates, after which the cell divides • Conjugation (sexual) –how bacteria exchanges genetic information –pili attach the bacteria Kingdom Archaebacteria • Prokaryotic, unicellular, auto or heterotrophic • usually live in harsh environments –oxygen free (anaerobic), very hot or acidic, or very salty environments • chemically different from other bact. –cell walls do not contain peptidoglycan 2) Kingdom Eubacteria • Prokaryotic, unicellular, auto and heterotrophic • “true” bacteria- can be found just about everywhere • Can be classified by shape, chemical composition, motility and metabolism Gram negative rods Gram positive - bacillus anthracis Identify Bacteria –Shape • Bacillus = rod • coccus = sphere • spirilla = spiral - Arrangement - diplo = two - strepto = chain - staphylo = cluster • Eubacteria can cause animal and plant disease but can also be beneficial. • They are essential parts of the food and pharmaceutical industry and can even be used to clean up oil spills. 3) Protista • unicellular, some simple multicelluar, all eukaryotic (nucleus present) • Some live freely, others are parasites • “catch all” kingdom –Protozoan animal like (ameobas and paramecium) –Algea plant like –Slime Molds fungus like Protozoan • Animal-like protists • heterotrophs • Classification based on movement –Sarcodina (pseudopodia) –Mastigophora (flagella) –Ciliophora (cilia) –Sporozoan (spores) Algae • Plant-like Protist • major ancestor to plants (autotrophic) • capable of photosynthesis (contains chlorophyll)- major source of O2 on earth • Reproduce sexually (Alternation of Generations) • unicelluar, multicellular,or colonial • phytoplankton - food for marine animals Phylum Euglenophyta - Euglena Slime Molds • Fungus-like Protist • multinucleated • no cytokenesis • decomposers Slime mold 4) Fungus • • • • Eukaryotic; multicelluar; heterotrophic extracellular digestion- absorb nutrients have sexual and asexual reproduction have cell walls made of chitin – hyphae- individual fibers form body – mycelium- thick mass of hyphae – septa- cross walls that divide hyphae into sections (not always present) 4 types of Fungi • Common Molds (Zygomycota)- ex. Breadmold • Club Fungi (Basidomycota)- ex. Mushrooms • Sac Fungi (Ascomycota)- ex. Yeast • Imperfect Fungi (Deuteromycota)- ex. Penicillin, athletes foot, ringworm Uses • Useful –decomposers-break down organic matter –antibiotics –industry - baking, brew, cheese –food - mushrooms, truffles • Harmful –spoiled food –plant/animal disease –ex. Dutch Elm Disease • parasite- tree diessaprophyte Basidiomycota - basidiocarp Ringworm 5) Plant Kingdom • Eukaryotic, multicellular, autotrophic • Take up water and nutrients in roots; make food in leaves (photosynthesis) • sexual reproduction (alternation of generations) • 4 major types: Nonvascular, Vascular seedless, Vascular naked seed, Vascular protected seed Adaptations to Land • Dominant Diploid (except Moss) • Cuticles-reduces dry out • deciduous- trees that drop leaves- reduce dry out • seed/pollen- pollination (replaced flagellated sperm) • flowers and fruits- attract pollinators and fosters dispersal of seeds Adaptations to Land • Vascular system- plants can grow tall away from water – Leaves-photosynthesis (stomata control gas exchange) – stems- support leaves – roots (hairs) obtain water and anchor • xylem- moves water • phloem-moves food Types of Plants • Moss- Nonvascular, require water for flagellated sperm, dominant phase is haploid, find close to the ground (water by osmosis) • Ferns- Vascular, seedless, have strong roots (rhizomes), large leaves (fronds), Sori(produce spores), dominant phase is diploid Types of Plants • Gymnosperm- Vascular, naked seeds (develop on the scales of female cones) diploid, pollen, examples are conifers, pine trees, evergreens • Angiosperm- Vascular, protected seed, flowering plants, diploid, pollen, ex. Grass, roses, fruit, beans –monocot or dicot Angiosperms have 2 classes • Monocot -- one cotyledon, narrow leaves with parallel leaves, flowers in multiples of 3, vascular tissue is scattered throughout (ex. Grass, lilies, corn) • Dicot--two cotyledon, broad leaves with branching veins, flowers in multiples of 4 or 5, vascular tissue in rings (ex. Roses, beans, clovers, trees) Plant Responses • Tropism- plant movement or growth in response to a stimulus – Phototropism- growth toward light – Geotropism (Gravitropism)- growth downward – Thigmotropism- response to physical touch of solid object – Hydrotropism- growth toward water 6) Animalia Kingdom • Eukaryotic, multicellular, heterotroph • Specialized cells from into tissues and organs • Most are able to move (some are sessile) • Invertebrates (no spinal cord) or Vertebrate (spinal cord) Invertebrates • No backbone • Symmetry- irregular, radial, or bilateral • Most have exoskeleton (hard outer casing) • Ex.--Sponges, Cniderians, Worms, mollusks, Arthropods (insects, crustaceans, spiders), echinoderms Porifera (Sponges)- sessile filter feeders, hermaphrodites, and bud, fragment, and regenerate Cnidarians (jelly fish, hydra)- sting prey with poisonous barbs in tentacles, incomplete dig. sys., Sex/Asex, Medusa (free swimming) and Polyp (sessil) Platyhelminthes (flat worms)decomoposers, some parasitic, 1st with cephalization, incomplete dig sys, flame cells, hermaphrodites and regeneration Nematoda (round worms)- parasitic, 1st with one-way complete dig sys., not hermaphrodites (ex. Ascaris/ pinworm/ vinegar eels) Annelida (segmented worms)-ex. Earthworm-complete dig syst, hydroskeleton, nephridia, closed circ syst (respiration across skin), developed nervous sys, hermaphrodites Mollusk (slugs, snails, clams, squid, octopus)- 3 regions(muscular foot, mantel, visceral mass), complete dig sys, nephridia, simple to complex nervous sys, internal fertilization, open or closed circulatory (very diverse) Arthropods (Crustaceans, Arachnids, Insects)- jointed appendages and body regions, exoskeleton, compound eyes, complete dig sys, nervous sys (brain), green gland or Malpighian tubules, Echinoderms (starfish)- spiny skin, radial symmetry, a water vascular system and an endoskeleton, nervous sys, complete dig, separate sexes, can regenerate Vertebrates • Chordates- hollow nerve tube, notochord, gill slits, post anal tail • vertebrae- bony segments (backbone) • distinct head (cephalization) • closed circulatory system • endoskeleton (axial and appendicular) • Ex: Fish, Amphibians, Reptiles, Birds, Mammals Fish- Agnatha (jawless), Chondricthyes (cartilogenous), Osteichthyes (boney), have 2 chambered heart, ectothermic Amphibians (frogs, toads, salamanders), aquatic larval stage, adapt to land, ectothermic, 3 chambered heart Reptiles (snakes, turtles, lizards, alligators)1st to have amniotic egg, skin covered with scales, ectothermic- 3 chambered heart Aves (Birds)-hollow bones (help fly), endothermic, 4 chambered heart) Mammals-covered with hair, nourish young with milk (mammary glands), endothermic, 4 chambered heart, Marsupials and Placental Viruses • Not a kingdom because they are non living organisms- noncellular • Core made up of DNA or RNA • Capsid made up of protein • Cannot replicate on own- uses enzymes and materials of host (lack ribosomes) • Host specific- only infect certain cells • ex. smallpox, measles, flu, colds, AIDS The Lytic Cycle The Lysogenic Cycle