Multiple choice

Which one of the following was most likely absent in free form in the primordial atmosphere at the time of origin of life?

  1. Methane

  2. Hydrogen

  3. Ammonia

  4. Oxygen

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Primitive atmosphere chiefly consisting of methane, ammonia, water vapour, hydrogen gas and was reducing. Oxygen was absent in primitive atmosphere. Oxygen came as a result of photosynthesis in green plants.