Unity and Diversity of Living Things Survey of Taxonomy and the Three Domains of Life.
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Transcript of Unity and Diversity of Living Things Survey of Taxonomy and the Three Domains of Life.
SYSTEMATICS Systematics - science of naming and
grouping organisms by their evolutionary relationships
Binomial nomenclature - assigning scientific names Each species is assigned a two-part
scientific name, usually in Latin, written in italics or underlined (if handwritten)
First word (genus name) is capitalized, the second word (species name) is not
Ex: polar bear = Urus maritimus Ex: red maple = Acer rubrum Ex: human = Homo sapiens
LEVELS OF CLASSIFICATION
Domain (most inclusive) Kingdom Phylum Class Order Family Genus Species (least inclusive)
DOMAIN BACTERIA
Prokaryotic Unicellular Cell walls contain peptidoglycan Ecologically diverse ranging from free-living
soil organisms to deadly parasites Some autotrophic, some heterotrophic Some need oxygen to survive (aerobic),
some are killed by oxygen (anaerobic) Only one kingdom within this domain:
Kingdom Eubacteria
DOMAIN ARCHAEA Prokaryotic Unicellular Cell walls do NOT contain peptidoglycan Live in very harsh environments Some autotrophic, some heterotrophic Some need oxygen to survive (aerobic),
some are killed by oxygen (anaerobic) Only one kingdom within this domain:
Kingdom Archaebacteria
IMPORTANCE OF PROKARYOTES
1) Ecological Importance: Essential in maintaining every aspect of the ecological balance of the living world Decomposers – recycling raw materials to
the environment, essential to sewage treatment & production of purified water
Producers – cyanobacteria are among the most plentiful photosynthetic organisms in the world & many food chains are dependent upon them
Nitrogen Fixers – converting nitrogen gas into useable forms
IMPORTANCE OF PROKARYOTES
2) Human UsesFood – yogurt, other dairy productsMedicine – making drugs for medical
treatments
IMPORTANCE OF PROKARYOTES
3) Disease – some bacteria can cause disease by destroying living cells or by releasing chemicals that upset homeostasisEx: Lyme disease, Tetanus,
Tuberculosis, Strep ThroatControlled by sterilization, disinfectantsPrevented by vaccines
DOMAIN EUKARYA
All eukaryotes contain a nucleus & other membrane-bound organelles
Four kingdoms:Protista FungiPlantaeAnimalia
EUKARYA - PROTISTS
Unicellular, colonial, or multicellular
Photosynthetic or heterotrophic
“Catch-all” kingdom – group of eukaryotes that did not fit into plants, animal, or fungus kingdom
ECOLOGICAL IMPORTANCE OF PROTISTS
Autotrophic Protists – photosynthetic protists at the base of the food chain makes much of the diversity of aquatic life possible Ex: Algae
Heterotrophic Protists – some heterotrophic protists engulf and digest their food, while others live by absorbing molecules from the environment. Ex: Paramecium, amoeba
Symbiotic Protists Mutualistic – algae help health of coral
reefs, Trichonympha live in guts of termites, helping them to digest cellulose
Parasitic – can cause intestinal disease, African Sleeping Sickness, & Malaria
EUKARYA - FUNGI
Heterotrophic – feed on dead or decaying organic matter
Secrete digestive enzymes into their food source, then absorb nutrients though their cell walls
Cell walls made of chitin Unicellular (yeasts) or
multicellular (mushrooms)
ECOLOGICAL IMPORTANCE OF FUNGI
Decomposers – many species of fungi help ecosystems maintain homeostasis by breaking down dead organisms and recycling essential elements and nutrients
Parasites – parasitic fungi can cause serious diseases in plants and animalsEx: smuts and rusts in plantsAthlete’s foot & ringworm
ECOLOGICAL IMPORTANCE OF FUNGI
Symbiotic Fungi: Lichens – mutualistic association
between a fungus and a photosynthetic partner (algae or cyanobacteria)
• Are often the first organisms to enter barren environments and help in early stages of soil formation
Michorrhizae – mutualistic association between a fungus and a plant root
• Estimates that 80-90% of all plant species have this sort of relationship
• Fungus collects water and minerals, bringing them to the root, plant supplies the fungi with the products of photosynthesis (sugars)