Question

'The origin of life' book was written by
A. Darwin
B. Oparin
C. Gray
D. Smith

Answer 1

Hint:-Spontaneous formation of organic monomers from the simpler raw substances is considered as the first step in the origin of life. The synthesis of first polymers from these monomers facilitated the formation of protobionts. Protobionts are assemblages of organic polymers and gradually acquired the characteristics of living cells.

 Complete step-by-step solution:-
The origin of life and evolution of various life forms have been described by various theories. Smith proposed the Clay hypothesis to describe the process of origin of life from the non-living particles such as clay and published the book entitled "Seven clues to the origin of life". Gray and his colleagues proposed the theory of endosymbiosis to explain the evolution of eukaryotic cell organelles such as mitochondria and chloroplasts from the prokaryotes. Darwin proposed the theory of natural selection to describe the evolution of various life forms. He described the theory in his book called "The origin of species by means of natural selection".
Once the theory of the spontaneous origin of life was refuted, Oparin and Haldane made a significant contribution to describe the process. Chemical evolution refers to the origin of the first life forms on the earth from the organic molecules. The concept was put forward by Oparin and Haldane.
Accordingly, the simple organic molecules such as simple sugars, amino acids, and nucleotides were spontaneously formed from the raw material present on the primitive earth. The reducing atmosphere of the primitive earth supported chemical evolution. It means that the atmosphere of the primitive earth was devoid of free molecular oxygen. Chemical evolution is considered the first step in the origin of life. Oparin described the concept of chemical origin of life in his book named "Origin of life".
So, the correct answer is option B. Oparin.

Note:- Biochemical origin of life as proposed by Oparin and Haldane cannot occur on the present-day earth. This is due to the presence of a significant amount of free molecules oxygen in its atmosphere. Therefore, reducing the atmosphere provided the required conditions for the spontaneous origin of organic substances on the primitive earth.