The plasmid used by Cohen and Boyer for the first transformation experiment was

Options

A. pSC 101
B. PUC 19
C. pBR 322
D. pBR 400

Answer

To answer the question about the plasmid used by Cohen and Boyer for the first transformation experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Scientists**: Recognize that the question refers to the pioneering work of scientists Cohen and Boyer in biotechnology.

2. **Understand the Context**: Cohen and Boyer conducted the first successful transformation experiment, which involved the introduction of foreign DNA into a bacterial cell.

3. **Know the Source of the Plasmid**: The plasmid used in their experiment was derived from *E. coli*, a common bacterium.

4. **Recall the Name of the Plasmid**: The specific plasmid used by Cohen and Boyer in their transformation experiment is known as pSC101.

5. **Evaluate the Options**:
- Option 1: pSC101 (Correct)
- Option 2: pUC19 (Not used in this experiment)
- Option 3: pBR322 (Not used in this experiment)
- Option 4: pBR400 (Not used in this experiment)

6. **Conclude the Answer**: Based on the information, the correct answer to the question is option 1, pSC101.

### Final Answer:
The plasmid used by Cohen and Boyer for the first transformation experiment was **pSC101** (Option 1).