OBJECTIVE LIFE SCIENCE
CELL BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Which gas was believed to be absent from early Earth’s atmosphere
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Hydrogen
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Nitrogen
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Oxygen
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Carbon
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Explanation:
Detailed explanation-1: -Earth’s original atmosphere was rich in methane, ammonia, water vapour, and the noble gas neon, but it lacked free oxygen.
Detailed explanation-2: -Oxygen is produced by plants by the process of photosynthesis, earlier there were no plants and vegetation, which’s why no oxygen in the early atmosphere.
Detailed explanation-3: -Two facts are known with certainty: Earth’s earliest atmosphere was essentially devoid of oxygen; and today’s atmosphere is composed of 21% oxygen. Most of the events that took place between these two time points are highly uncertain.
There is 1 question to complete.