Prokaryotes and Eukaryotes Flashcards
Name some evidence of early prokaryote life
Fossil stromatolites
Fossil microorganisms
Carbonaceous matter
What were stromatolites colonies of?
Cyanobacteria
What are the two types of fossil microorganisms?
Silicified in cherts
Acritarchs preserved in siltstone
When did life roughly evolve?
3.45 billion years ago
How long did prokaryotes dominate the planet?
2 billion years
What were some early oxygen sinks?
Volcanic gases in early atmopshere react with oxygen
Dissolved iron reacts with oxygen to from BIFs (Banded Iron Formations)
Faculative aerobes
When was the Great Oxygenation Event?
2.4 - 1.8 billion years ago
What needs to be considered when thinking of the origin of eukaryotes?
When were conditions suitable for the origin of eukaryotes
Fossil evidence of eukaryotes
What is some fossil evidence of early eukaryotes?
Some acritarchs are large enough to suggest eukaroytes ~2 billion years ago
What are the three theories of eukaryote origin? Which has the most evidence?
Theory 1 - Symbiosis (ate other bacteria and became symbiotic)
Theory 2 - Elaboration of a cell membrane
Theory 3 - Multiple symbiotic events (each component of a eukaryote was a prokaryote)
Theory 3 has the most evidence
What early prokaryote did mitochondria originate from?
Faculative aerobe, proteobacterium
Why would an early eukaryote engulf an early mitochondria?
Early eukaryotes could not cope with higher oxygen levels so engulfed a prokaryote that could
What early prokaryote did chloroplasts originate from?
Cyanobacteria
What early prokaryote did flagella and cilia POSSIBLY originate from?
Spirochaete bacteria
