Assertion (A) : The earliest organisms that appeared on the Earth were non-green and presumably anaerobis.
Reason (R ) : The first autotrophic organisms were the chemoautotrophs that never released oxygen.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion.
B. It both Assertion & Reason are true but the reason is not the correct explanation of the assertion.
C. If Assertion is true statement but Reason is false.
D. It both Assertion and Reason are false statements.

Answer

b

Explanation

The first livin organisms originated among organic molecules and in oygen free atmosphere. They pressumably obtained energy by fermentation of some of these organic molecules. They were non green and anacrobes. Capable fo resppiring in absenes of oxyge. They depended on the existing organic heterotrophs. Then came autorophs when the supply of existing organic molecules were exhausted. These organisms were capable of producing their onw organic molecules by chemosynthesis. they synthesized food from inorganic molecules. Photoautotrophs were also anaerobie at first but later on oxygen releasing photosynthetic developed.