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Assertion : The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
Reason :The first autotrophic organisms were the chemoautotrophs that never released oxygen.
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
If the Assertion is correct but Reason is incorrect.
If both the Assertion and Reason are incorrect.
Solution
The earliest organisms that appeared on the earth were heterotrophic because of reducing atmosphere and the first autotrophs were chemoautotrophs.
An anaerobic organism does not require oxygen for growth and may even die in its presence. Chemotrophs are the first organisms that appeared on earth & obtain energy by the oxidation of electron donating molecules in their environments. These molecules can be organic (organotrophs) or inorganic (lithotrophs). The chemotrophs utilize solar energy and can be either autotrophic or heterotrophic.
