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24 Cards in this Set
- Front
- Back
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What bacteria and Archaea have in common
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-Prokaryotes
-No membrane bound organelles -Circular chromosome -Some are motile -Binary Fission -Conjugation -Some are motile |
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What is conjugation and why is it important?
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Transfer of DNA by direct cell to cell contact
• Transfer copies of plasmids (loops of DNA) via a conjugation tube -Brings about genetic diversity...which not otherwise happen |
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Difference in cell walls...
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Bacteria: Cell walls made of peptidoglycan
(sugars and amino acids) Archaea: Cell walls vary (polysaccharides), but no peptidoglycan |
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Differences between the two...
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Bacteria are pathogenic! There are not pathogenic Archaea!
-No histones in bacteria, archaea posses histones. -Bacteria: translation begins with f-met...Archaea translation begins methionine -Bacteria don't have introns, archaea do. |
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Archaea Bacteria Rank Crenarchaeota
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Only in the extreme environments
• Extreme Thermophile - Water that is Extremely HOT (110 C) • Hot springs, volcanic vents, hydrothermal vents on ocean floor |
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Archaea
Rank Euryarchaeota |
Live in every conceivable habitat • Extreme Halophiles - In the Great Salt Lake & the Dead Sea. • Extreme Acidophiles - ACIDIC (pH less than 2)
Also in hot springs, volcanic vents, hydrothermal vents on ocean floor, in the soil, in waterways, & in your gut! |
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modern definition of speciation:
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a group of actually or potentially interbreeding populations which are relatively isolated from other such groups
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-Allopatric speciation
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physically divided population:
1.-dispersal & colonization 2.Vicariance ex: squirells and grand canyon |
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Sympatric specation
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•Speciation within the same geographical area in wich genetic eventscan cause reproductive isolation
Ex: soapbunny beatles native tree-.>small fruit Non-native->large fruit also an example of disruptive selection |
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Both types of barriers to interbreeding
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Pre and post zygotic speciation
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Name all 6 of the pre zygotic barriers.
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• 1.Geographic isolation
• ex; Oak trees, Orioles •2.Ecological isolation • Same are, distinct habitats o Ex; Tigers-> forests, Lion-> Grasslands •3.Temporal isolation • Dividing by time • Ex; birds, amphibians •4. Behavioral isolation • Perform for distinct breeding call or display •5. Mechanical isolation • parts don’t fit •6. Prevention of gamete fusion • sperm can’t survive female reproductive tract • sperm can’t penetrate egg membrane |
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Post zygotic isolating mechanism
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• 1. Developmental incapability
• ex; leopard frogs (sometimes no life) • ex; (lack of vigor, cannot reproduce) |
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Name in order the big five extinctions...
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o 1. Ordovician
o 2. Devonian o 3. Permian-Triassic o 4. Triassic-Jurassic o 5. Cretaceous-Tertiary |
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• Ordovician
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o Mostly sea life at this time: fungi, algaue, fish
o 2nd longest extinction o Godwana drifted over south pole o Phase of global cooling and glaciations • Sea levels were drastically lowered |
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• Devonian
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o 375 MYA Paleozoic, Mesozoic era
o ferns, fungi, insects, amphibians, fish o Heavily affected marine life: 70 % of all marine species o Since warm water species most severely affected Suspect another round of global cooling or Volcanic ash on water |
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• Permian-Triassic
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oThe BIG one
o251 MYA oAmphibians, ferns, gymnosperms, mammal like reptiles oEstimated 90-95% of species died off or ‘BIT IT’ o50 million years before life on land fully recover it’s biodiversity oAsteroid impact or magma surfaced over asia • Global cooling oTHIS JUST IN • Evidence for volcanic activity in Siberia.. • C02 released • Global warming low O2 in water… • Hydrogen sulfide gas |
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• Triassic-Jurassic
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o205 MYA- Mesozoic era
oReptiles, amphibians, gymnosperms, dinasaurs oHit many reptiles and large amphibians oMany possible causes • Meteor, volcanoes, continental movement |
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• Cretaceous-Tertiary (K-T) extinction
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o 65 mya- Mesozoic/Cenozoic era
o dinosaurs, flowering plants, birds, live birth mammals • OK: Amphibians, Turtles, Mammals, Insects • NOT OK: Dinosaurs, land plants, reptiles, birds • ~ 10 million years to recover the biodiversity of mammals |
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What killed the Dino-daddy's
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• What killed the dinosaurs?
o Climate change? • Atmosphere heated up even before impact • Thermal energy before impact • Displacement of matter from earth o Impact hypothesis-1970 • High quantities of iridium element in rock • (rare on earth, common in asteroids) • shocked quartz and micro-tektites • Crater the size of Italy found in NW corner of YUKATAN peninsula • Huge cloud of SO2 = Acid Rain & Scattering Solar Radiation Wildfires adding to smog • Earthquakes and Tsunami |
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Mass extinction now?
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o The Human Asteroid
o Many new species, extinction, endangered o Habitat disappearance o Hunting/over harvesting o Why? • Introducing species • Landscape alterations • Lowering species diversity • Global warming o Solutions • DNA, seed banks • Save only the one’s in crisis o Extinct species • Golden Toads-Costa Rica- Habitat loss • Western black rhino- West Africa- poaching and habitat loss |
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Two main ways Archaea and bacteria are different
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DNA and Metabolic processes
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Until when did we use two kingdom classification system?
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1969 we changed to a five kingdom system proposed by RH whittaker
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Carl Woese...tell me a lil about him
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1990's proposed 3 domain system
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Give the meaning of the three pre-fixes
Bacter, Arhaea, Eu |
o Greek Bacter = rod or staff
o Archaea = Greek Archae = ancient o Eukarya = Greek Eu = true |
