Oxygen and Life Essay

1199 Words5 Pages
Bio Lab 101
Smithsonian Laboratory

Early Atmosphere
1. How abundant was oxygen in the early atmosphere?

The earth’s early atmosphere contained only small amounts of free oxygen, produced by the reaction of water vapor with sunlight. The oxygen rich atmosphere that developed later and on which oxygen breathing life now depends was result of the origin and spread of organisms capable of photosynthesis.

2. What evidence do scientists have that the oxygen content of our atmosphere has increased since the earth’s origin?

By looking at the rustiness of ancient rocks, scientists attempt to trace the evolution of oxygen in the atmosphere.

3. Why is oxygen more abundant in the atmosphere today? spread of organisms that
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It also had helium.

3. What circumstances may have fostered the development of chains of amino acids and nucleotides?

The circumstances that may have played a part in the development of these chains were the conditions in which they were formed. They formed in small ponds that periodically heated and dried, leaving traces of these water molecules that would play a part in producing the chains.

4. What are the characteristics of the ancestors of living cells and what could they “do”?

The ancestors of living cells, also known as the “forerunners”, were single celled, with a ring shaped coil of DNA. They would gather into clumps, absorb smaller molecules, rearrange them, and released them as waste products.

5. Why is water important to life?

Water is the medium in which biochemical reactions occur, playing an extreme importance in creating and sustaining life here on earth.

6. What are the “true” hallmarks of life?

complicated network of energy producing an energy consuming reactions plus the ability of the entire system plus the ability of the entire system to produce itself was the hallmark of true life.

7. What molecular evidence do scientists have that all life is at least distantly related and has a common ancestor? The possible varieties of proteins are virtually unlimited even for the primitive proteins life ferredoxin. If one calculates the possible combinations of percent amino acids along a ferredoxin
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