How old is the earth?
4.6 billion years old
most important thing about primitive atmosphere?
it was anaerobic
The primitive atmosphere had..
CO, CO2, N2, H2
what caused the primordial soup?
lightning, volcanic activity
contents of primordial soup
carbs, lipids, amino acids, nucleic acids
what is a protobiont?
aggregate of abiotically produced molecules surrounded by membrane
first organisms to evolve?
no distinct nucleus
no membrane bound organelles
where did prokaryotes originally live?
what did prokaryotes live on?
heterotrophic (fed on organic molecules)
were prokaryotes aerobic or anaerobic?
first thing capable of photosynthesis
cyanobcteria (blue-green algae)
pigments for cyanobacteria
chlorophyll a and accessory pigments
what was cyanobacteria capable of?
fixing atmospheric n2
importance of phtosynthesis?
causes organism to be autotrophic and the water splitting created o2 as a biproduct,
what organisms can split water?
ones with chlorophyll a
what's so great about a bi product of 02?
ozone (o3) intercelts radiation
when did eukaryotes evolve?
organized into chromosomes and associated with histone proteins
complex membrane bound organelles
how did the intracellular membrane system evolve so that eukaryotes could evolve?
the plasma membrane invaginateed and folded
how did mitochondria evolve for eukaryotes?
mitochondria endosymbiont theory: the cell engulfed an aerboic prokaryote and the prokaryote evolved into mitochondria
how did chloroplasts evolve?
serial or sergequential endosymbiosis: photosynthetic cells were engulfed by larger cells
four evidences of endosymbiosis evolution theories
they have circular dna and aren't assoiciated with histone proteins, they're semi-autonomous, ribosomes are similar to prokaryote ribosomes
general characteristics of protists?
unicellular or simple multicellular
basically don't fit in anywhere else
ancestor history of protists?
they're polyphletic (no single immediate ancestor
examples of protists
mold, amoebas, protozoans, alga, spirogyra, giardia,
where are protists on the food chain?
at the base!
uses of protists?
bad thing about protists?