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

Options

A. i,ii,iii,iv
B. i,iii,ii,v
C. ii,iii,i,iv
D. ii,iii,iv,i

Answer

To determine the correct sequence of events in the origin of life, we need to analyze the provided steps:

1. **Synthesis of organic monomers**: The first step in the origin of life involves the formation of simple organic molecules (monomers) such as amino acids and nucleotides. This is essential because these monomers serve as the building blocks for more complex structures.

2. **Synthesis of organic polymers**: Once the organic monomers are available, they can combine to form organic polymers. This includes proteins (formed from amino acids) and nucleic acids (formed from nucleotides). This step is crucial as it leads to the creation of more complex molecules that are necessary for life.

3. **Formation of protobionts**: The next step involves the aggregation of these organic polymers into protobionts. Protobionts are simple, cell-like structures that can maintain an internal environment different from their surroundings. They are considered precursors to true living cells.

4. **Formation of DNA-based genetic systems**: Finally, the protobionts evolve to develop genetic systems, leading to the formation of DNA-based life forms. This step marks the transition from non-living to living entities, as DNA carries the genetic information necessary for reproduction and functioning.

Based on this analysis, the correct sequence of events in the origin of life is:
**II. Synthesis of organic monomers → III. Synthesis of organic polymers → I. Formation of protobionts → IV. Formation of DNA-based genetic systems.**

Thus, the correct order is:
**II → III → I → IV.**