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AP Biology
Bacteria Archae-bacteria
AnimaliaFungiProtista Plantae
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Formation of earth
Molten-hot surface ofearth becomes cooler
Oldest definite fossilsof prokaryotes
Appearance of oxygenin atmosphere
Oldest definite fossilsof eukaryotes
First multicellularorganisms
Appearance of animalsand land plants
Colonization of landby animalsPaleozoic
Mesozoic
Cenozoic
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The evolutionary tree of life can be documented with evidence.1. Fossils2. Genetics3. Physiology
The evolutionary tree of life can be documented with evidence.1. Fossils2. Genetics3. Physiology
AP Biology
Archaebacteria&
Bacteria
Classification Old 5 Kingdom system
Monera Protists Plants Fungi Animals
Prokaryote
Eukaryote
AP Biology
Classifying Life Molecular data
challenges 5 Kingdoms Monera was too diverse
2 distinct lineages of prokaryotes
Protists are still too diverse not yet sorted out
AP Biology
3 Domain system Domains = “Super” Kingdoms
Bacteria Archaea
extremophiles = live in extreme environments methanogens halogens thermophiles
Eukarya eukaryotes
protists fungi plants animals
AP Biology
KingdomProtista
KingdomFungi
KingdomPlantae
KingdomAnimalia
KingdomArchaebacteria
KingdomBacteria
AP Biology
Prokaryotes
Domain Bacteria
Domain Archaebacteria
DomainBacteria
DomainArchaea
DomainEukarya
Common ancestor
AP Biology
Bacteria live EVERYWHERE! Bacteria live in all ecosystems
on plants & animals in plants & animals in the soil in depths of the oceans in extreme cold in extreme hot in extreme salt on the living on the dead
AP Biology
Bacterial diversityrods and spheres and spirals… Oh My!
AP Biology
Prokaryote Structure Unicellular
bacilli, cocci, spirilli
Size 1/10 size of eukaryote cell
1 micron (1um)
Internal structure no internal compartments
no membrane-bound organelles only ribosomes
circular, naked DNA not wrapped around proteins
prokaryotecell
eukaryote cell
AP Biology
Variations in Cell Interior
aerobic bacteriumcyanobacterium
(photosythetic) bacterium
internal membranesfor photosynthesislike a chloroplast(thylakoids)
internal membranesfor photosynthesislike a chloroplast(thylakoids)
internal membranes
for respiration
like a mitochondrion
(cristae)
internal membranes
for respiration
like a mitochondrion
(cristae)
AP Biology
Prokaryote Cell Wall Structure
peptide sidechains
cell wallpeptidoglycan
plasma membrane
protein
Gram-positive bacteria
Gram-negative bacteria
peptidoglycan
plasmamembrane
outermembrane
outer membrane of lipopolysaccharides
cell wall
peptidoglycan = polysaccharides + amino acid chainslipopolysaccharides = lipids + polysaccharides
AP Biology
Prokaryotic metabolism How do bacteria acquire their energy &
nutrients? photoautotrophs
photosynthetic bacteria chemoautotrophs
oxidize inorganic compounds nitrogen, sulfur, hydrogen…
heterotrophs live on plant & animal matter decomposers & pathogens
AP Biology
Genetic variation in bacteria Mutations
bacteria can reproduce every 20 minutes binary fission
error rate in copying DNA 1 in every 200 bacteria has a mutation
Genetic recombination bacteria swap genes
plasmids small supplemental
circles of DNA
AP Biology
Genetic variation in bacteriaTransformation Taking in DNA
from the environment Cell surface
receptors recognize closely related DNA and take it in!
Griffith experiment, showing genetic material could be transferred
AP Biology
Genetic variation in bacteria Transduction
Bacteriophages Specialized viruses that
infect bacteria only Take DNA from one
bacteria to another Like a mosquito
carrying a parasite
AP Biology
Genetic variation in bacteriaConjugation Two bacteria are temporarily
joined by a pilus One way only
AP Biology
Bacteria as pathogens Disease-causing microbes
plant diseases wilts, fruit rot, blights
animal diseases tooth decay, ulcers anthrax, botulism plague, leprosy, “flesh-eating” disease STDs: gonorrhea, chlamydia typhoid, cholera TB, pneumonia lyme disease
AP Biology
Bacteria as beneficial (& necessary) Life on Earth is dependent on bacteria
decomposers recycling of nutrients from dead to living
nitrogen fixation only organisms that can fix N from atmosphere
needed for synthesis of proteins & nucleic acids plant root nodules
help in digestion (E. coli) digest cellulose for herbivores
cellulase enzyme
produce vitamins K & B12 for humans
produce foods & medicines from yogurt to insulin
AP Biology
Any Questions??