Oxygen & Carbon Dioxide in the Atmosphere Flashcards
What increased the atmospheric concentration of oxygen?
Photosynthesis
What is photosynthesis?
The process in which light energy is used to produce glucose and oxygen from carbon dioxide and water.
What was the first photosynthetic organisms to evolve?
How long ago did this happen?
ALGAE was the first photosynthetic organisms to evolve. This happened about 2.5-2.7 BILLION years ago.
What, after algae, began to evolve over the next billion years?
What did this cause?
Photosynthesising plants. This led to an increasing rate of oxygen accumulating in the atmosphere.
What began to evolve once a threshold of concentration of oxygen was reached?
More complex life forms, such as ANIMALS.
What removed carbonates from the oceans and why?
The evolution of marine animals removed carbonates from the oceans as the animals used these to build their shells and skeletons.
What three factors caused atmospheric carbon dioxide to decrease?
Marine animals, oceans, and photosynthesis.
