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HOW LIFE HAS AFFECTED THE EARTH?

Last updated about 1 year ago
17 questions
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1

The first bacteria on Earth _____ use oxygen.

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1

Photosynthesis (by cyanobacteria and plants) ______ oxygen gas.

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1

2 ways scientists think Earth started to get more oxygen in the air is by:

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1

Wait, how do we know how much oxygen was present before humans existed?

Because scientists have analyzed oxygen isotopes from gases trapped in __________.

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What do you already know about EARLY EARTH'S ATMOSPHERE?

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Predict how oxygen amounts have changed over time on Earth.
What would the line graph look like?

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What is Table 1 data showing?

USING Table 1 data, on a separate graph paper, set up and graph "How OXYGEN Has Changed Over Time on Earth".

Hint: You can copy how to set it up.
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1

Does your graph on your paper look like anything you predicted in #6?

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What is Table 2 data showing?

Now add the 10 GEOLOGIC EVENTS from Table 2 to the correct spots on your graph paper.
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Look at the data table 1 again.

Which gas has made up the LARGEST portion of the Earth's atmosphere for most of Earth's history?

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Which gas did not appear until about 2 billion years ago?

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Which gas has been almost nonexistent since about 3 billion years ago?

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When limestone deposits became common, which gas appeared in the atmosphere?

2

Look at your graph paper.

Which event from the 10 you copied is correlated with (related to) the increase in oxygen (and the decrease in CO2)? WHY?

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Look at your paper graph.

How would you describe the TREND of oxygen levels throughout Earth's history?

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If cyanobacteria started doing photosynthesis 3bya, how come it took 1 billion years to start seeing oxygen in the air?

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If Venus and Mars' atmospheres have mostly CO2 and Earth's atmosphere is mostly N and O...

WHY do you think our atmosphere is so different?