Which of the following experimentally demonstrated that life comes only from pre-existing life?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Louis Pasteur
Option (1) Alfred Wallace — Incorrect. Wallace, working in the Malay Archipelago, came to the same idea of natural selection as Darwin.
Option (2) Hugo de Vries — Incorrect. De Vries worked on the evening primrose and proposed the mutation theory of evolution.
Option (3) Louis Pasteur — Correct. Louis Pasteur showed by careful experiments that life comes only from pre-existing life. In pre-sterilised flasks no life appeared, while in flasks open to air new organisms arose; this ended the theory of spontaneous generation.
Option (4) S.L Miller — Incorrect. Miller made amino acids from CH4, H2, NH3 and water vapour with electric discharge, supporting the chemical origin of life.
NCERT Extract:
Origin of Life – “… Louis Pasteur by careful experimentation demonstrated that life comes only from pre-existing life. He showed that in pre-sterilised flasks, life did not come from killed yeast while in another flask open to air, new living organisms arose from ‘killed yeast’.”