Practice question

Volcanic outgassing models and Miller-Urey experimental design suggest primitive atmosphere comprised methane, ammonia, molecular hydrogen and water vapor, without free oxygen. These gases provided carbon, nitrogen and hydrogen for organic synthesis when energized by lightning and ultraviolet radiation. Their reducing character prevented oxidation of intermediates, enabling accumulation of amino acids in oceanic soup. Modern understanding supports CH4, NH3, H2, H2O as dominant components before photosynthetic oxygenation transformed atmosphere to oxidizing state. This concept integrates genetics, ecology and molecular evidence, frequently tested in NEET, GATE and CSIR-NET, highlighting links between genotype, phenotype and environment.