AP Biology BacteriaArchae- bacteria AnimaliaFungiProtistaPlantae 4500 4000 3500 3000 2500 2000 500 1500 0 1000 Formation of earth Molten-hot surface of.

AP Biology

Bacteria Archae-bacteria

AnimaliaFungiProtista Plantae

4500

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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

Mill

ion

s o

f y

ears

ag

o

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CH

EA

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OIC

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

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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

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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

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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

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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

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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

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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

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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

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Genetic variation in bacteriaConjugation Two bacteria are temporarily

joined by a pilus One way only

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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??