Kingdom Kingdom Monera Monera What are PROKARYOTES? TEM of dividing cell • No No nucleus nucleus • No No chloroplasts chloroplasts • No No mitochondria mitochondria ey are ancient life forms ey are ancient life forms known as known as bacteria bacteria major clades of bacteria major clades of bacteria Archaebacteria Archaebacteria & Eubacteria & Eubacteria Methanogens Extreme Thermophiles Extreme Halophiles Cyanobacteria Cyanobacteria (Blue-green algae) & other Gram negative bacteria Gram negative bacteria Gram positive bacteria Gram positive bacteria
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Kingdom Monera What are PROKARYOTES? TEM of dividing cell No nucleus No chloroplasts No mitochondria They are ancient life forms known as bacteria Two.
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Kingdom Kingdom MoneraMonera
What are PROKARYOTES?
TEM of dividing cell
• No No nucleusnucleus• No No chloroplastschloroplasts• No No mitochondriamitochondria
They are ancient life formsThey are ancient life forms
known as known as bacteriabacteria
Two major clades of bacteriaTwo major clades of bacteria
Gas vacuoles;• Small ribosomes Small ribosomes (70S) for protein (70S) for protein synthesissynthesis
but have DNA & RNAbut have DNA & RNA
but have but have pigments, pigments, thylakoids & thylakoids & enzymes for enzymes for PSPSbut have but have respiratory respiratory chain & chain & membranesmembranes
Ancient organisms Ancient organisms but well suited to but well suited to earth’s habitatsearth’s habitats
Unicells to Unicells to complex multicell complex multicell organismsorganisms
TrichodesmiumTrichodesmium blooms can blooms can cover cover 2x102x1066 km km22 and be seen via and be seen via satellitessatellites
NASANASA
DiversityDiversity
Being comprised of
only 20% peptidoglycan, the cell wall
of Gram-negative
bacteria is much thinner than Gram-
positive bacteria. Gram-negative bacteria have two unique regions which surround
the outer plasma membrane: i) periplasmic space and ii) lipopolysaccharide layer.
• periplasmic space separates the outer plasma membrane from the peptido-glycan layer.• lipopolysaccharide layer is adjacent to the exterior peptidoglycan layer
(C)(C)• Cyanophycin Cyanophycin (N)(N)• Poly PPoly Pi i bodiesbodies
GrowthGrowth• Every cell can Every cell can
True branchingTrue branching
False branching False branching
• MulticellulMulticellul
ar ar organismsorganisms
: :
Fragments regrowFragments regrow
““Spores”Spores” regrow
Akinetes germinateAkinetes germinate
• BranchingBranching
Growth &Growth &morphologymorphology
Binary Fission(cell division)
Produces genetically identical “offspring” or twins
Increases the numbers of cells in the population by exponential growth, 2n
Cell division for unicellsCell division for unicells:
1
1
1
1
4
1
2
8
16 cells
Divisions may be every 15 to 20 minDivisions may be every 15 to 20 min
0
300
600
900
1200
1 3 5 7 9
Rounds of cell division
# ce
lls
in p
op
ula
tio
n
Growth &Growth &morphologymorphology
Unicell populations grow rapidly
Starting with 1 cell:10 rounds of division
1,000+ cells
It’s not It’s not unusual to unusual to
have 10 have 10 66 to to 10108 8 cells / mL in cells / mL in
“blooms”“blooms”
Cyanotech pondsCyanotech ponds
Developmental lineagesDevelopmental lineages
Evaluate adult form to gain insight Evaluate adult form to gain insight in possible in possible evolutionary evolutionary processes.processes.
Step-by-step acquisition of new traits Step-by-step acquisition of new traits via genetic change.via genetic change.
Examine reproductive cells and other Examine reproductive cells and other characters characters as additional data.as additional data.
Useful means to construct evolutionary hypotheses Useful means to construct evolutionary hypotheses to test with molecular data.to test with molecular data.
Growth &Growth &morphologymorphology
Order Chroococcales
Evolution has taken a Evolution has taken a simple shapesimple shape
Developmental Lineage #1
to more complex but related to more complex but related formsforms:• Multicellular generaMulticellular genera
All cells appear virtually identical - internally
Genetic changeGenetic change
Order Chroococcales
MerismopediaMerismopedia
Diversity Diversity
MicrocystisMicrocystis
Growth &Growth &morphologymorphology
Coordinated binary
fission of all cells in
colony
1 colony
2 colonies
Multicellular Multicellular organisms divide but organisms divide but increase the number increase the number of entities in the of entities in the populationpopulation
Growth &Growth &morphologymorphology
Order Chamaesiphonales
Developmental Lineage #2
Evolution has taken a simple shape:Evolution has taken a simple shape:
• attachment to the substrateattachment to the substrate
• spores released from upper end of cellspores released from upper end of cell
Growth &Growth &morphologymorphology
Evolution has taken a simple shape:Evolution has taken a simple shape:
• constrained cells into chainsconstrained cells into chains• formed arrays of trichome(s) in sheathsformed arrays of trichome(s) in sheaths
trichomes + sheathtrichomes + sheath• false branching can result
Diversity Diversity Order Nostocales
Growth &Growth &morphologymorphology Order Nostocales
False branchingFalse branching
1. Rupture of sheath and cells1. Rupture of sheath and cells
: :
2. Remaining cells at 2. Remaining cells at both ends continue to both ends continue to growgrow3. Both trichomes push 3. Both trichomes push
through weakened sheath through weakened sheath
What to look for?What to look for?
Is there a change in Is there a change in the plane of cell the plane of cell division?division?
New Cell TypesNew Cell Types
Nitrogen fixation Nitrogen fixation supports protein supports protein synthesissynthesis1. Low N in environment1. Low N in environment
2. Cell differentiates as a 2. Cell differentiates as a specialized cell, the specialized cell, the heterocystheterocyst3. Creates setting for 3. Creates setting for Nitrogenase enzymeNitrogenase enzyme
Growth &Growth &morphologymorphology Order Nostocales
Nitrogen fixation & Nitrogen fixation & AzollaAzolla in rice fields in rice fields replace fertilizersreplace fertilizers1. Low N in environment1. Low N in environment
National Geographic:http://www.nationalgeographic.com/world/0010/bacteria/bacteria.html
An underworld of hydrogen sulfide harbors life-forms awesome and awful: http://www.nationalgeographic.com/ngm/0105/feature4/index.html
Margulis, L. (1970). Origin of eukaryotic cells. Yale University Press, New Haven.
Scientific American Extremophiles: http://www.spaceref.com/redirect.html?id=0&url=www.sciam.com/0497issue/0497marrs.html
Mereschowsky, C., (1910). Theorie der zwei Plasmaarten als Grundlage der Symbiogenesis, einer neuen Lehre von der Entstehung der Organismen., Biol. Centr. 30, 353-367, 1910.
Mereschowsky, C., (1905). Über Natur und Ursprung der Chromatophoren im Pflanzenreiche., Biol. Centr. 25, 593-604 & 689-691.
NASA interactive pageNASA interactive page
http://nai.arc.nasa.gov/_global/shockwave/http://nai.arc.nasa.gov/_global/shockwave/g3_matgallery.swfg3_matgallery.swfPowers of ten interactive page:Powers of ten interactive page:http://microscopy.fsu.edu/primer/java/scienceopticsu/powersof10/index.html