Question

Louis Pasteur’s view on the origin of life is that
(a) Life originated within six days
(b) Life originated spontaneously from the living organisms only
(c) Life originated spontaneously from the non-living substances
(d) Life came from other planets

Answer 1

Hint: Louis Pasteur is the scientist who used his swan neck experiment to disprove the theory of abiogenesis or spontaneous generation completely. He then proposed the theory of biogenesis and firmly believed in it.

Complete Answer:
The theory of biogenesis is credited to Louis Pasteur and it states that the origin of new living organisms is from previously existing living organisms. This is completely different from what was believed prior which was that living organisms were spontaneously generated from non-living things. This theory was known as the theory of spontaneous generation of abiogenesis ( genesis from non-living things) and was firmly believed by people during that time as it was in accordance with the special creation theory where God created humans out of the mud. But Pasteur was able to convince everyone by carefully conducting experiments in a swan-neck flask to show life did not arise spontaneously.

Additional information: Let us look in detail at the Swan-neck experiment performed by Louis Pasteur.

- Pasteur sterilized two swan neck flasks and filled them with nutrients containing broth which will allow organisms to grow on it.
- The swan neck ensured that the broth won’t be contaminated by outside air.
- No organism arose from the broth showing that living organisms cannot arise spontaneously.
- But when we broke one of the swan necks, living organisms appeared in that one thus proving that organisms can come from pre-existing organisms.
So, the correct option is ‘(b) Life originated spontaneously from the living organisms only’.

Note:
- Other scientists who worked in proving the theory of spontaneous generation were Francesco Redi, Lazzaro Spallanzani, and John Tyndall.
- Tyndall effect is named after scientist John Tyndall who researched this extensively.
- Louis Pasteur also developed a method known as Pasteurization which we use to prepare pasteurized milk.