Who said "abiogenesis first but biogenesis ever since"?

Options

A. Haldane
B. Pasteur
C. Fox
D. Oparin

Answer

To answer the question "Who said 'abiogenesis first but biogenesis ever since'?", we can follow these steps:

### Step 1: Understand the Key Terms
- **Abiogenesis**: This refers to the process by which life arises naturally from non-living matter, such as simple organic compounds.
- **Biogenesis**: This is the principle that living organisms arise from existing living organisms.

### Step 2: Analyze the Statement
The statement "abiogenesis first but biogenesis ever since" implies that life initially originated from non-living materials (abiogenesis), but since that origin, all life has come from pre-existing life (biogenesis).

### Step 3: Identify the Scientists
We need to determine which scientist made this statement. The options provided are:
- Haldane
- Pasteur
- Fox
- Oparin

### Step 4: Evaluate Each Option
- **Haldane**: While he contributed to theories about the origin of life, he did not make this specific statement.
- **Pasteur**: Known for his work in microbiology and fermentation, he did not propose this idea.
- **Fox**: He worked on the origins of life and proposed the concept of microspheres but did not make this statement.
- **Oparin**: He is known for his work on the chemical basis of the origin of life and is credited with the statement in question.

### Step 5: Conclusion
Based on the analysis, the correct answer is **Oparin**.