Which of the following statements describes the theory of spontaneous generation?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Life came out of decaying and rotting matter like straw and mud.
Before the experiments of Louis Pasteur, many people believed that living things could arise on their own from non-living rotting matter. This old belief was the theory of spontaneous generation.
Option (1) Life came out of decaying and rotting matter like straw and mud. — Correct. For a long time it was believed that life came out of decaying and rotting matter like straw and mud. This is the theory of spontaneous generation.
Option (2) Life comes from pre-existing life. — Incorrect. This is the conclusion of Louis Pasteur. His experiments with killed yeast in pre-sterilised flasks showed that life comes only from pre-existing life, and this dismissed spontaneous generation.
Option (3) Units of life called spores were transferred to different planets including earth. — Incorrect. This is the idea of panspermia, held by early Greek thinkers, who thought units of life called spores were transferred to different planets including earth.
Option (4) The first form of life came from pre-existing non-living organic molecules. — Incorrect. This is the proposal of Oparin and Haldane. They held that the first life arose from non-living organic molecules such as RNA and protein, after a period of chemical evolution.
NCERT Extract:
Origin of Life – “Did life come from outerspace? Some scientists believe that it came from outside. Early Greek thinkers thought units of life called spores were transferred to different planets including earth. ‘Panspermia’ is still a favourite idea for some astronomers. For a long time it was also believed that life came out of decaying and rotting matter like straw, mud, etc. This was the theory of spontaneous generation. Louis Pasteur by careful experimentation demonstrated that life comes only from pre-existing life.”
Origin of Life – “Oparin of Russia and Haldane of England proposed that the first form of life could have come from pre-existing non-living organic molecules (e.g. RNA, protein, etc.) and that formation of life was preceded by chemical evolution …”