diversity of life - domain iv part a: biological...
TRANSCRIPT
www.BioEdOnline.orgBioEd Online
Why Do We Classify Organisms?
Biologists group organisms to representsimilarities and proposed relationships.
Classification systems change withexpanding knowledge about new andwell-known organisms.
Tacitus bellus
www.BioEdOnline.orgBioEd Online
Populus tremuloidesQuaking Aspen
Classification and Phylogeny
Binomial Nomenclature
Hierarchical Classification
Systematics: Evolutionary Classification
www.BioEdOnline.orgBioEd Online
Carolus von Linnaeus(1707-1778)
Swedish scientist who laidfoundation for moderntaxonomy
Binomial Nomenclature
Carolus von Linnaeus
Two-word naming systemGenus
Noun, Capitalized,Underlined or Italicized
SpeciesDescriptive, Lower Case,Underlined or Italicized
www.BioEdOnline.orgBioEd Online
Hierarchical Classification
Taxonomic categoriesKingdom KingPhylum PhilipClass CameOrder OverFamily ForGenus GreenSpecies Soup
www.BioEdOnline.orgBioEd Online
Kingdoms and Domains
Bacteria Archaea Eukarya
Bacteria Archaea Protista Plantae Fungi Animalia
Monera Protista Plantae Fungi Animalia
The three-domain system
The six-kingdom system
The traditional five-kingdom system
www.BioEdOnline.orgBioEd Online
Systematics:Evolutionary Classification of Organisms
Systematics is the study of the evolution of biologicaldiversity, and combines data from the following areas.
Fossil recordComparative homologiesCladisticsComparative sequencing of DNA/RNA amongorganismsMolecular clocks
www.BioEdOnline.orgBioEd Online
Taxonomic Diagrams
Mammals Turtles Lizards andSnakes
Crocodiles Birds Mammals Turtles Lizards andSnakes
Crocodiles Birds
CladogramPhylogeneticTree
www.BioEdOnline.orgBioEd Online
Dichotomous Keys Identify Organisms
Dichotomous keys versus evolutionary classification
Dichotomous keys contain pairs of contrastingdescriptions.
After each description, the key directs the user toanother pair of descriptions or identifies the organism.
Example:1. a) Is the leaf simple? Go to 2
b) Is the leaf compound? Go to 3
2. a) Are margins of the leaf jagged? Go to 4b) Are margins of the leaf smooth? Go to 5
www.BioEdOnline.orgBioEd Online
Introduction to Phylogenetic Kingdoms
Monera (Eubacteria and Archaebacteria) -Prokaryotes, with or without peptidoglycan in cell walls
Protistia – Eukaryotes, diverse, not fungi, plants,or animals
Fungi – Eukaryotes, multicellular (except yeasts),heterotrophic, chitin in cell walls
Plantae – Eukaryotes, multicellular, non-motile,autotrophic, cell wall containing cellulose
Animalia – Eukaryotes, multicellular, motile,heterotrophic, no cell wall
www.BioEdOnline.orgBioEd Online
Streptococcus mutans(can causeendocarditis anddental caries)
Bacillus anthracis(spores can live insoil for years)
The Kingdom Monera - Eubacteria
Common name: Bacteria
Unicellular prokaryotes
No introns in genome
Peptidogylcan in cell wall
Basic shapes are cocci, bacilli, spirilla
Diverse nutrition and respiration
Reproduce by binary fission, conjugation,transformation, and transduction
www.BioEdOnline.orgBioEd Online
The Kingdom Monera - Archaebacteria
Cell wall does not contain peptidogylcan
Cell membrane contains unusual lipids not found inother organisms
Genes are interrupted by introns
Classified into three groups:Methanogens—poisoned by O2
Thermaphiles—live in extreme temps.Halophiles—live in high saline
www.BioEdOnline.orgBioEd Online
Entamoeba histolytica
The Kingdom Protista or Protoctista
A classification problem
Unicellular, colonial, andmulticellular forms
Autotrophic and heterotrophic
Some move with flagella,pseudopods or cilia
Animal-like, plant-like andfungus-like groups
Reproduce by mitosis andmeiosis
www.BioEdOnline.orgBioEd Online
The Kingdom Plantae
Multicellular, non-motile, cell wall withcellulose, mostly autotrophic
Plant life cycles
Plant Structures relate to plant needsSunlight, water and minerals, gasexchange,Reproduce without water to transmitmale gamete (in Angiosperms)Vascular tissue, roots, stems, leaves,seeds, flowers
Sunflowers inFargo, North Dakota
www.BioEdOnline.orgBioEd Online
Major Groups of Plants
Three traditional groupings:Bryophytes—nonvascular plantsPteridophytes — vascular, seedless plantsSeed plants
GymnospermsAngiosperms
Ginkgo biloba
Ginkgos are oftenvery long-lived.Some specimens arethought to be morethan 3,500 years old.
www.BioEdOnline.orgBioEd Online
The Kingdom Animalia
No cell wall
Heterotrophic
Motile
Sexual reproduction
Three distinct layers of tissues(except sponges)
Multi-celled/specialized tissuesand functions
Distinct body plan
www.BioEdOnline.orgBioEd Online
Invertebrates and Vertebrates Animals
Invertebrates99% of the Animal KingdomAbsence of backboneIncludes sponges, cnidarians,mollusks, worms, arthropods, andechinoderms
VertebratesInternal skeleton (bone or cartilage)Includes fish, amphibians, reptiles,birds, and mammals
Asian ladybeetleHarmonia axyridis
Notice the “false”white eye markingsbehind the head.
www.BioEdOnline.orgBioEd Online
HymenopteraDialictus zephrum
Txodes scapularisDeer tick
Invertebrate Animals
Sponges
Cnidarians
Worms
Mollusks
Arthropods
Echinoderms