Transcript Unity and Diversity of Living Things

Unity and Diversity
of Living Things
Survey of Taxonomy and the Three
Domains of Life
SYSTEMATICS
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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. First word (genus
name) is capitalized, the second word
(species name) is not.
EX/ polar bear = Ursus maritimus
Red maple = Acer rubrum
Human = Homo sapiens
LEVELS OF
CLASSIFICATION
Domain (most inclusive)
 Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 Species (least inclusive)
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DOMAINS OF LIFE
3 Domains of Life
 Archaea (prokaryotic)
 Bacteria (prokaryotic)
 Eukarya (eukaryotic)
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DOMAIN BACTERIA
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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 Eubacteira
DOMAIN ARCHAEA
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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 Archaebacteira
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
2) Human Uses
 Food – yogurt, other dairy products
 Medicine – making drugs for medical treatments
3) Disease – some bacteria can cause disease by destroying living
cells or by releasing chemicals that upset homeostasis
 EX’s/ Lyme disease, Tetanus, Tuberculosis, Strep Throat
 Controlled by sterilization, disinfectants
 Prevented by vaccines
DOMAIN EUKARYA
All Eukaryotes: contain a nucleus &
other membrane-bound organelles
 Four Kingdoms
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Protista (protists)
 Fungi
 Plantae
 Animalia
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PROTISTS
Unicellular, Colonial, or Multicellular
 Photosynthetic or Heterotrophic
 Catchall kingdom – group of
eukaryotes that did not fit into plants,
animal or fungus kingdom
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ECOLOGICAL IMPORTANCE
OF PROTISTS
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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
Red blood cell
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)
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ECOLOGICAL
IMPORTANCE OF FUNGI
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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 animals
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EX/smuts and rusts in plants
Athlete’s foot & ringworm
Symbiotic Fungi:
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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).
PLANTS
Multicellular
 Cell walls with cellulose
 Autotrophic
 Have chloroplasts
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ANIMALS
Multicellular
 Heterotrophic
 No cell walls
 Most can move
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