Inquiry:   Earth Space Earth History     name ________________

Pages 584 – 593  please submit on Friday

1) What 2 gases dominated Earth’s very early atmosphere? Why are these gases not present today?

2) What organisms produced the abundant O2 that is present today early in the Precambrian Era.

3) What forces are at work to destabilize the concentration of O2 at any point in time? (not in the text)

4) How do geologists determine when O2 levels began to increase at a point in time?

5) How is the formation of O2 important in the creation of the ozone layer and why is the ozone layer important to the evolution of terrestrial life?

6) What are the 2 sources of water on Earth and where is it possibly still coming from at the present time?



 

7) How did the oceans become salty?

8) What is the theoretical age of life on Earth?

9) Stanly Miller performed an experiment that showed that under the theoretical atmospheric conditions that existed on Earth in the early Achean Eon. What chemicals were produced in his experiment that indicate the possibility that life could arise spontaneously.

10) Complete the following

Amino Acids combine to become ____________________

Nucleic Acids combine to form     ____________________