grade 8 archaea
Post on 14-Apr-2017
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Domains
Archaea
Bacteria
Eukarya
Prokaryotes
Eukaryotes
Prokaryotes
Endosymbiotic Theory
4
Eukaryotes
Any organism with one or more
cells that contain a membrane-
bound nucleus (that holds the
genetic material) and
organelles.
Domains
Archaea
Bacteria
Eukarya
Prokaryotes
Eukaryotes
Viruses
small infectious
agents comprised
of genes (DNA or
RNA) inside a
protein coat
Viruses
• In isolation, viruses show none of
the expected signs of life. They do
not respond to stimuli, they do not
grow, they do not do any of the
things we normally associate with
life.
Viruses and Disease
Viruses and Disease
• common cold
• influenza
• chickenpox
• Ebola
• AIDS
• avian influenza
• SARS
• Zika
• Rabies
• And many others..
Domains
Archaea
Bacteria
Eukarya
Prokaryotes
Eukaryotes
Domain Archaea
Cell type: Prokaryotic
Cell membrane: Strong bonds
enable it to withstand
extreme environments
Cell wall: Present in almost all
(pseudopeptidoglycan)
Domain Archaea
Mode of Nutrition:
autotrophs
(lithoautotrophs or
photoautotrophs)
Reproduction: asexual
Habitat: mostly extreme
environments but also
living in swamps, soils,
and seas.
Halophiles
These are archaea that
can thrive above 20-
25% salinity.
Note: Seawater has
3.5% salinity.
Extreme halophiles
These salt-loving archaea
sometimes turn the waters
pink or magenta. Pink
halophiles have
bacteriorhodopsin and
use this for a type of
photosynthesis that does
not produce oxygen.
Thermophiles
These are organisms that
live in extremely hot
environments. Some
archaea are thermophiles
and can withstand
temperatures up to 121° C.
Extreme thermophiles
These are Archaea from
hot springs and other high
temperature environments.
Some can grow above the
boiling temperature of
water.
Alkaliphiles /
Acidophiles
These are archaea that
can thrive at extreme pH
conditions.
Acidophile = pH 0 – 4
Alkaliphile = pH 8 - 14
Acidophiles / Alkalophiles
Other archaea exist in very
acidic or alkaline conditions.
One of the most extreme
archaean acidophiles is
Picrophilus torridus, which
grows at pH 0.
Methanogens
They make methane
(natural gas) as a waste
product. They are
found in swamp
sediments, sewage,
and in buried landfills.
Methanogens
In the future, they could
be used to produce
methane as a byproduct
of sewage treatment or
landfill operation.
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