The sequence of origin of life may be

Options

A. Inorganic materials `rarr` Organic materials `rarr` Colloidal aggregate `rarr` Eobiont `rarr` Cell
B. Organic materials `rarr` Inorganic materials `rarr` Colloidal aggregate `rarr` Eobiont `rarr` Cell
C. Inorganic materials `rarr` Organic materials `rarr` Eobiont `rarr` Cell `rarr` Colloidal aggregate
D. Organic materials `rarr` Inorganic materials `rarr` Eobiont `rarr` Cell `rarr` Colloidal aggregate.

Answer

To determine the correct sequence of the origin of life based on the theory of chemical evolution proposed by O'Parin and Haldane, we can break down the process into several key steps:

### Step-by-Step Solution:

1. **Inorganic Materials**: The first step in the origin of life involves the presence of inorganic materials. These include elements and compounds that were available on the early Earth, such as water, methane, ammonia, and hydrogen. These inorganic constituents are essential as they provide the building blocks for the next stage.

2. **Formation of Organic Materials**: The second step is the formation of organic substances or biomolecules from these inorganic materials. Through various chemical reactions, simple organic compounds like amino acids, nucleotides, and fatty acids are synthesized. This process is often referred to as abiogenesis.

3. **Formation of Colloidal Aggregates**: The third step involves the aggregation of these organic molecules into colloidal structures. These aggregates, which can include proteins and lipids, create a more complex environment that resembles living systems. They are not yet living cells but show some properties of life, such as the ability to maintain a distinct internal environment.

4. **Development of Proto-cells (Eobionts)**: The fourth step is the formation of proto-cells or eobionts. These structures are formed from the colloidal aggregates and are characterized by having a membrane-like boundary that separates them from their surroundings. They exhibit properties such as self-replication and metabolism, which are essential characteristics of living cells.

5. **Evolution of Living Cells**: Finally, through evolutionary processes, these proto-cells evolve into true living cells. Over time, these cells diversify and give rise to the complex biodiversity we observe today.

### Final Sequence:
- Inorganic Materials → Organic Materials → Colloidal Aggregates → Proto-cells (Eobionts) → Living Cells