Question

Following are the two statements regarding the origin of life :
(1) The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
(2) The first autotrophic organisms were the chemoautotrophs that never released oxygen.
Which one of the following options is correct?

• A. (1) is correct but (2) is false
• B. (2) is correct but (1) is false
• C. Both (1) and (2) are correct
• D. Both (1) and (2) are false

Answer 1

The correct option is C Both (1) and (2) are correct

The two statements regarding the origin of life are both correct according to the theory of Abiogenesis. According to this, life arose from non-living matter such as simple organic compounds. And life evolved in the oceans during a period when the atmosphere was reducing - in the sense that, it was containing $H_2$, $H_{2}O$. $N{H}_3$, $C{H}_4$, and $C{O}_2$, but no free $O_2$. So the earliest organisms that appeared on earth were non-green (no photosynthetic pigments) and they were anaerobes. The first autotrophic organisms were chemoautotrophs which never released oxygen and photosynthesis would arise eventually as an alternative energy source when the natural foods ran short.