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How old is the earth?
N2, H

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


membrane-bound droplets

first organisms to evolve?


prokaryote nuclei?

no distinct nucleus

prokaryote dna?


prokaryote organelles?

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?

aerobic atmosphere
ozone (o3) intercelts radiation

when did eukaryotes evolve?

2.1 bybp

eukaryotic nuclei?

well defined

eukaryotic dna?

organized into chromosomes and associated with histone proteins

eukaryotic organelles?

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
similar membranes

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?


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