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29 Cards in this Set
- Front
- Back
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What elements did the Big Bang produce (primarily)? |
Hydrogen Helium Lithium Berylium |
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What is the sun made up of? |
Hydrogen (74.9%) Helium (23.8%) Oxygen (1%) Carbon (0.3%) Neon (0.1%) Iron (0.1%) |
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How was the sun created? |
Nuclear fusion |
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How does the sun keep earth habitable? |
It is always growing hotter, in increasing atmospheric oxygen and decreasing atmospheric CO2 |
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When did the sun form? |
4.567 billion years ago |
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What will the sun become in 5 billion years? |
A red giant, then a white dwarf |
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What are some signs of life? |
-an atmosphere not in chemical equilibrium - sufficient mass to retain atmosphere - goldilocks zone - photosynethis -protection against ultraviolet light |
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How do tides, caused by the moon affect the earth? |
- increase biodiversity - give biological cues to time reproduction - promoted colonisation of life on land |
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What is the Theia theory? |
The earth collided with a planet called Theia, and the moon was created. At the same time, earth cooled, oceans formed, tectonic plates began to shift, promordial soup created, complex life could begin to develop |
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What characteristics of water make it essential for life? |
Liquid at Earth's temperature I've floats but melts under pressure, allowing glacier flow, fertilisation of land, release of rock minerals, erosion of high mountains Polar molecule Neutral pH Central to acid/base neutrality and enzyme function |
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What are the features of living organisms? |
Reproduction Transformation of energy Growth Stimuli response Homeostasis |
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What are the theoretical stages of life on Earth? |
1) monomers (simple amino acids) 2) polymers (proteins, nucleic acids) 3) membranes (protobionts) 4) RNA world (enzymes and information) |
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How were monomers formed? |
No oxygen in atmosphere yet, Earth cooled and oceans formed, intense UV radiation and volcanic activity occurred, comet impact |
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How were polymers formed? |
In chemically reducing environments such as deep sea vents or volcanic openings, these organisms could form from amino acids and nucleotide bases. |
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What are protobionts? |
Collections of organic molecules enclosed in a membrane. The membrane is formed by self organising lipids. They are non living. |
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What does the RNA world refer to? |
The development of a genetic code to provide a heritable mechanism. Came before DNA |
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When was the first life on Earth (detected)? |
Prokaryotes (archea and bacteria) - 3.9 Gyears ago Fossils (Stromatolites) - 3.5 Gyears ago |
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What are prokaryotes? |
Organisms that have no nucleus or organelles, can live in many environments. First organisms to colonise land. |
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What was the Great Oxygenation Event? |
Cyanobacteria prokaryotes released oxygen which causes iron oxide to precipitate from oceans. Oxygen eventually got into the atmosphere around 2.7-2.2 Gyears ago. Killed many prokaryotes 'Snowball Earth' |
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When were the first Eukaryotes around? |
Around 2.1 Gyears ago, maybe longer. Eg. Mitochondria, chloroplasts -endosymbiosis (eukaryotes engulfed prokaryotes) |
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What is the light harvesting complex? |
A structure inside a membrane made up of proteins and carotenoid. It absorbs photons from sunlight and emitted to tla reaction centre where CO2 is fixed. |
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What are the three domains of life? |
Bacteria Archea Eukaryota |
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What are tectonic plates powered by? |
Internal heat from gravitational collapse cosmic collisional energy radioactivity |
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How long do most species last? |
1 - 10Myears |
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Which species has hardly changed? |
Horseshoe crab |
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What are the four main mass extinctions? |
The Great Dying Dinosaur Diversification Mammal Diversification Holocene Extinction |
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How fast is the solar system travelling? |
220km per second |
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How quickly does the sun complete one orbit? |
225 - 250 million years |
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What are the dominant metazoa? |
Menatodes and arthropods |
