Evolution Of Life Question 29
Question: In primordial atmosphere, when the living, organism evolved, the respiration process was:
Options:
A) Anaerobic as it released more energy.
B) Aerobic as it was more complex.
C) Aerobic as it released more energy.
D) Anaerobic because early atmosphere contained little or no oxygen.
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Answer:
Correct Answer: D
Solution:
[d] Primordial conditions on the earth were high temperature, volcanic storms, reducing atmosphere containing $ C{H_{4,}}NH_3,H_2, $ etc.
There was no oxygen on the primitive earth.
The first living organisms developed among the organic molecule and in oxygen free atmosphere.
They presumably obtained energy by the fermentation of organic compounds and were almost certainly heterotrophs, requiring readymade organic materials as food.
They were also anaerobic i.e.
capable of respiration in the absence of oxygen.