Question

What was proposed by Oparin and Haldane on the origin of life?

Answer 1

They propose that the first life form could have come from pre-existing non-living organic molecules such as protein, RNA, etc. and that life formation was led by chemical evolution.

Complete step-by-step answer:
Scientists J.B.S Haldane, British scientist and Aleksandr Oparin, Russian biochemist working independently on the same idea of concern the condition needed for the origin of life form on earth. Both think that organic molecules could be formed from abiogenic material in the presence of an external source of energy. For example ultraviolet radiation. This primitive atmosphere was reducing and comprising water vapour and ammonia among other gases. They suspected that first life forms originated in the warm primitive ocean were heterotrophic, that is which obtained nutrients from other existing compounds rather than the autotrophic, who generates their nutrients with help of sunlight or inorganic substance.
Oparin believed that coacervates developed the life, spontaneously formed microscopic, spherical aggregates of lipid molecules. These molecules are held together by the electrostatic force. They can be the precursors of cells. He worked with coacervates and said that the enzymes responsible for the biochemical reaction. These enzymes work more efficiently when found inside the membrane-bound spheres than when free in aqueous solution.
Haldane was unknown with this work of Oparin, he suggested that simple organic molecules formed first. These molecules formed in the presence of UV light became increasingly complex and finally formed cells. Haldane and Oparin ideas became the foundation for much of the reaches on abiogenesis that took place in later years.

Note: The origin of life on the earth can be understood only against the background of the origin of the universe. Most of the scientists believed that the first appearance of life is the formation of biomolecules that is chemical evolution. Most of the experts said that all the life forms present today had evolved by common descent from a single primitive life form. The big bang theory explains the origin of the universe.