Evolution — BIOLOGY STD 12 Science — Question

1. Early earth had innumerable free atoms of all those elements, which were essential for the formation of protoplasm.
2. Free atoms combined to form molecules and simple inorganic compounds.
3. The primitive atmosphere contained gases like CO₂, CO, N, H₂, etc. The nitrogen and carbon of the atmosphere combine with metallic atoms, forming nitrides and carbides water vapour and metallic carbides reacted to form the first organic compounds, methane (CH₄). Later on hydrogen cyanide was formed.

Torrential rain must have dissolved away and carried with it salts and minerals, and ultimately accumulated in the form of present occurance. Thus ancient oceanic waters contained large amounts of dissolved NH₃, CH₄, HCN, nitrides, carbides, various gases and elements.

The early compounds interacted and produced simple organic compounds such as simple sugars, nitorgenous bases, amino acids, glycerol, fatty acids, etc under the action of external forces such as solar radiations electrical discharges and like lightning and high energy radiations.