Question

Which of the following was absent in the atmosphere at the time of origin of life?

• A. $N{H}_3$
• B. $N_2$
• C. $O_2$
• D. $H_2$

Answer 1

The correct option is C $O_2$

Experiments were perfomed based on the theory of chemical evolution given by Oparin and Haldane which stated that the formation of life was preceded by the formation of organic molecules from inorganic substances present in the Earth's reducing atmosphere containing ammonia, methane, hydrogen, etc.