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Sloan [31]
3 years ago
9

Which statement correctly describes how the amount of ofoxygen in the earth's atmosphere has changed over time?

Biology
1 answer:
dmitriy555 [2]3 years ago
3 0

Answer:

Oxygen levels are generally thought to have increased dramatically about 2.3 billion years ago. Photosynthesis by ancient bacteria may have produced oxygen before this time. ... In addition, early plants and algae began to release oxygen at a faster rate. Oxygen levels then showed a dramatic increase.

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