Question

Atmosphere of earth just before the origin of life consisted of:

• A. ${\mathrm{CH}}_4$, ${\mathrm{NH}}_3$ , $H_2$ and water vapours.
• B. ${\mathrm{CH}}_4$, $O_3$, $O_2$ and water vapours.
• C. Water vapours, ${\mathrm{CH}}_4$, ${\mathrm{NH}}_3$ and oxygen.
• D. ${\mathrm{CO}}_2$, ${\mathrm{NH}}_3$, and ${\mathrm{CH}}_2$.

Answer 1

The correct option is A ${\mathrm{CH}}_4$, ${\mathrm{NH}}_3$ , $H_2$ and water vapours.

The primitive atmosphere was reducing type due to the lack of free molecular oxygen. The early atmosphere contained ammonia (${\mathrm{NH}}_3$), water vapour ($H_{2}O$), hydrogen ($H_2$), methane (${\mathrm{CH}}_4$).