1-Conquering Land Flashcards
Approximately how long ago did the Earth form?
~4.6 billion years ago
What did the Earth only obtain ~4,500 million years ago?
Its present day size.
Name 4 gases abundant in the primitive atmosphere.
Nitrogen (N2)
Water (H2O)
Carbon Dioxide (CO2)
Methane (CH4)
Name chemicals found in primitive oceans.
Ammonia (NH3) Hydrogen gas (H2)
In what ways could early bacteria get energy?
Photosynthesis
Extract H2 from the primitive ocean
Extract hydrogen sulphide from volcanoes
How did oxygen build up in the atmoshpere?
Bacteria respiring produced oxygen.
O3 (Ozone) built up
What did the build up of oxygen and creation of an atmosphere do?
Protected from harmful U.V. rays
Facilitated the colonization of land
In what type of rock do fossils typically form?
Sedimentary rock
in what circumstances does the best preservation occur?
Sudden deposition of sediment ,e.g mudslide, volcanic eruption etc.
What type of rock are the oldest fossils in the world found in?
Chert (in Autstralia)
How old were the oldest fossils in the world?
What organisms are fossilised in these rocks?
3.46 billion years old
Cyanobacteria
What is an alternative name for cyanobacteria?
Blue-green algae
How is cyanobacteria different to bacteria and algae?
Cyanobacteria are prokaryotic, algae is eukaryotic.
Cyanobacteria are photosynthetic and can be multicellular, bacteria are non-photosynthetic and and only unicellular.
The first what was found 3.5 b.y.a?
The first prokaryote
The first what was found 2.1 b.y.a
First eukaryote
