Question
Question: Which of the following is the correct sequence of events in the origin of life? I. Formation of pr...
Which of the following is the correct sequence of events in the origin of life?
I. Formation of protobionts
II. Synthesis of organic monomers
III. Synthesis of organic polymers
IV. Formation of DNA-based genetic systems
A. II, III, I, IV
B. II, III, IV, I
C. I, II, III, IV
D. I, III, II, IV
Solution
In evolutionary biology, the term abiogenesis/ informally the origin of life, is referred to as the natural process by which life has given rise from non-living matter, such as simple organic compounds.
Complete answer:
Majority of the biologists believed that life evolved on Earth through non-living molecules or chemicals which then became ordered into collections of molecules which were capable of self-replication and metabolism.
Remember that,
The primitive reducing earth's atmosphere was very rich in water vapour, carbon dioxide, nitrogen carbon monoxide, and hydrogen. UV light, high temperature and lightening helped as sources of energy for chemical reactions between gases mentioned above to make simple organic like sugars, amino acids, fatty acids, glycerol’s and nucleotides (II).
These above discussed, simple organic compounds were washed from atmosphere to ocean by raining. They served as monomers for forming complex organic compounds in the ocean (III).
This was followed by assembling of organic polymers to make “protobionts” – it is a self-organized, and endogenously ordered, spherical in shape collection of lipids which is proposed as a stepping-stone to the birth of the origin of life (I).
RNA was the first genetic material which was then replaced later by DNA which is more stable and less reactive (IV).
Therefore, the correct answer is option A.
Additional information: Miller in his classic experiment- tested if the conditions on prehistoric earth would have possibly allowed inorganic synthesis of organic molecules, that led to the creation of living organisms.
Note:
Keep in mind, evolution can't be stopped and it can happen by varying mechanisms like natural selection and genetic drift. As our environment is always varying, natural selection is always occurring. Humans are also still evolving, and it is unlikely to change in the future.