What did $S.L.$ Miller observe in his experimental set-up?

Stanley Miller simulated the conditions of pre-biotic Earth using a spark-discharge apparatus. Which organic compounds were observed by him upon analyzing the end product of his experiment?

Stanley Miller observed the synthesis of ........ during his experiment.

Photosynthetic bacteria that produce oxygen are believed to have evolved approximately how many years ago?

According to Oparin,which one of the following was absent in the primitive atmosphere of the Earth?

What was used in the experiment to prove that life arises only from pre-existing life?