Diversity in Biology Taxonomy Taxonomy is the science

Diversity in Biology

Taxonomy • Taxonomy is the science of naming and classifying organisms • A taxon is a group of organisms in a classification system • The levels of classification from broadest to most specific: • • Domain Kingdom Phylum Class Order Family Genus Species

Binomial Nomenclature & Classification • Aristotle first classified organisms into two groups • plants • animals • Carolus Linnaeus classified organisms based on similarities and developed the binomial nomenclature (two name system of naming) where each organism is assigned a two-part name. Aristotle Carolus Linnaeus

Binomial Nomenclature • First name is the Genus name which always has the first letter capitalized • Second name is the species • When printed – use italics • When hand-written – underline the Genus and species

Evolutionary History of an Organism • Phylogeny- the evolutionary history of a species • Cladistics- a classification system based on evolutionary history (Phylogeny) • Cladogram- a branching diagram that shows the evolutionary history of a species or group of organisms. • Shows when in history certain traits developed.

Not Quite Living: Viruses • Viruses cannot reproduce without a host cell, cannot grow or develop, cannot respond to stimuli (examples: HIV, HPV, influenza) • Infect living organisms by taking over their cellular functions • Lytic viruses take over immediately and DESTROY the host cells. • Lysogenic viruses incorporate their DNA into host DNA, but they do not take over immediately. • Retroviruses have RNA instead of DNA.

Lytic vs. Lysogenic Cycle

3 Domains • Archaea- includes kingdom Archaebacteria • Bacteria- includes kingdom Eubacteria • Eukarya- ALL eukaryotic organisms (includes kingdoms Protista, Fungi, Plantae, Animalia)

6 Kingdoms • Archaebacteria • Eubacteria • Protista • Fungi • Plantae • Animalia

Archaebacteria • Prokaryotes, unicellular, autotrophs or heterotrophs, cell wall lacking peptidoglycan • Examples: Methanogens, halophiles • Live in extreme environments (ie. Deep sea vents, Geothermal pools)

Eubacteria • Prokaryotes, unicellular, autotrophs or heterotrophs, cell wall made of peptidoglycan. • Examples: Escherichia coli, Streptococcus aureus • True bacteria that can live practically everywhere • Gram-positive bacteria- no outer membrane around cell wall, stains purple • Gram-negative bacteria- outer membrane around cell wall, stains pink, harder to kill. Coccus- round shaped bacteria Bacillus- rod shaped bacteria Spirillus- spiral shaped bacteria

Protista • Eukaryotes, mostly unicellular, autotrophs or heterotrophs, some have cell walls. • Animal-like Protists (Protozoans)- all unicellular & mobile heterotrophs • Examples: Amoebas, Paramecium (ciliate), Giardia (flagellate), plasmodium (causes malaria). • Plant-like Protists- unicellular (plankton) & multicellular (algae), all autotrophs • Examples: Euglena, diatoms, kelp. • Fungus-like Protists- mostly multicellular decomposers that can move. • Examples: Slime molds, water molds, downy mildews

Fungi • Eukaryotes, mostly multicellular, heterotrophs (decomposers), cell walls made of chitin, cannot move • Examples: Mushrooms, yeasts, molds • Reproduce Sexually using spores • Body is made of threadlike structures called hyphae

Plantae • Eukaryotes, multicellular, autotrophs, cell walls made of cellulose, cannot move • Non-vascular plants- transports materials by osmosis & diffusion, must live close to water (example: mosses) • Seedless vascular plants- reproduce using spores, transport materials through xylem & phloem (example: Ferns) mosses ferns

Plantae (continued) • Vascular plants- transport materials through xylem & phloem, can survive in many habitats. • Non-seed plants (use spores) & Seed Plants • Two Types of Seed Plants • Gymnosperms • Phylum Coniferophyta – evergreens & conifers • Angiosperms • Phylum Anthophyta – flowering plants

Animalia • Eukaryotes, multicellular, heterotrophs, have no cell walls, mobile • Invertebrates (have no spine) • Vertebrates (have a spine)

Invertebrate Animals • Phylum Porifera – Sponges • Phylum Cnidaria – Jellies, anemone, coral, hydra • Phylum Platyhelminthes – Flatworms (ex. Tapeworm, planaria) • Phylum Nematoda – Roundworms (ex. Heartworms, pinworms) • Phylum Annelida – Segmented worms (ex. Earthworms, leeches)

Invertebrate Animals (continued) • Phylum Mollusca • Class Gastropoda – snails • Class Cephalopoda – octopus, squid, cuttlefish, sea slugs, nautilus • Class Bivalvia – hinged shells; clams, mussels, oysters, scallops, abalone

Invertebrate Animals (continued) • Phylum Arthropoda – hard exoskeleton, jointed appendages • Arachnids – spiders, scorpions, mites, ticks, horseshoe crabs • Crustaceans – pill bugs, barnacles, krill, copepods, shrimp, crayfish, crabs, lobsters • Insects • Centipedes & Millipedes

Sea Star Invertebrate Animals (continued) • Phylum Echinodermata – move using tube feet Sea Urchins • Examples: Sea stars, brittle stars, sea urchins, sea cucumbers, sand dollars • Phylum Chordata – • Examples: Tunicates (aka. Sea squirts), Lancelets Tunicates Sand Dollar Sea Cucumber

Veterbrate Animals (Subphylum Vertebrata) • Class Agnatha- Jawless Fish • No scales, gill slits, fins, ectothermic (body temp. controlled by external environment) • Class Chondricthyes- Cartalaginous Fish • Scales, gills, fins, ectothermic (body temp. controlled by external environment) • Class Osteichthyes- Bony Fish • Scales, gills, fins, ectothermic (body temp. controlled by external environment)

Veterbrate Animals (Subphylum Vertebrata) Amphibians • Class Amphibia- Amphibians • Moist smooth skin, breathe through skin & lungs (some gills), need water to breed (jellylike eggs), ectothermic (body temp. controlled by external environment) • Class Reptilia- Reptiles • Scales, lays leathery amniotic eggs on land, ectothermic (body temp. controlled by external environment) Reptiles

Veterbrate Animals (Subphylum Vertebrata) • Class Aves- Birds • Feathers, beaks, wings, hollow bones (flying birds), lays hard amniotic eggs, endothermic (maintains a constant internal body temperature)

Veterbrate Animals (Subphylum Vertebrata) • Class Mammalia- Mammals • Hair, live birth, produces milk for young (mammary glands), complex brain/nervous system, endothermic (maintains a constant internal body temperature) • Subclass Monotremata: (egg layers – platypus & echidna) • Subclass Marsupial: (pouch – koala, kangaroo, opossum) • Subclass Eutheria: (placental mammals – humans, whales, dogs, etc. )