The free genes started absorbing the organic compounds from the prebiotic soup and evolved into

Options

A. Anaerobic autotrophs
B. Aerobic heterotrophs
C. Aerobic protobionts
D. Anaerobic heterotrophs

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the evolution of free genes that absorbed organic compounds from the prebiotic soup. We need to identify what they evolved into.

2. **Defining Prebiotic Soup**: The prebiotic soup refers to a mixture of organic compounds that existed on early Earth, which is believed to have been crucial for the origin of life. This theory was proposed by scientists Oparin and Haldane.

3. **Role of Free Genes**: Free genes are considered to be the initial genetic material that could absorb organic compounds from the prebiotic soup. These genes are essential for the development of life.

4. **Evolutionary Pathway**: The free genes, by absorbing these organic compounds, evolved through various stages:
- They first became **anaerobic autotrophs**, which are organisms that do not require oxygen and can produce their own food.
- Next, they evolved into **aerobic heterotrophs**, which require oxygen and consume organic material for energy.
- Following this, they transitioned into **aerobic protobionts**, which are primitive cell-like structures.
- Finally, they evolved into **anaerobic heterotrophs**, which rely on organic compounds for energy without using oxygen.

5. **Identifying the Correct Answer**: Based on the evolutionary pathway outlined, the final evolution of the free genes absorbing organic compounds from the prebiotic soup leads to the formation of **anaerobic heterotrophs**.

6. **Conclusion**: Therefore, the correct answer to the question is **anaerobic heterotrophs**.