Question map
Which one of the following is in the correct sequential order in which these appeared under simulated primitive earth condition ?
Explanation
The Miller–Urey context begins with a reducing early atmosphere containing methane among primary gases released during degassing of the young Earth [1]. Under electric discharge or UV, methane with NH3/H2 produces simple organics and gaseous intermediates such as hydrogen cyanide (HCN) formed from the initial gases [3]. HCN and aldehydes then participate in pathways that generate nitriles (including amino‑nitrile intermediates of the Strecker/cyanohydrin chemistry), which subsequently hydrolyse or are converted into amino acids; analytical re‑examinations of Miller‑type experiments support this intermediacy sequence [3]. Thus the correct chronological order is methane → hydrogen cyanide → nitriles → amino acids (Option 1).
Sources
- [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 2: The Origin and Evolution of the Earth > Evolution of Atmosphere and Hydrosphere > p. 15
- [2] https://www.pnas.org/doi/10.1073/pnas.1402894111
- [3] https://pages.uoregon.edu/jschombe/glossary/miller_urey_experiment.html