A pair of bacteria used during the construction of first artificial recombinant DNA molecules

Options

A. Haemophilus and Salmonella
B. Salmonella and Bacillus
C. Escherichia and Haemophilus
D. Salmonella and Escherichia

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the pair of bacteria used during the construction of the first artificial recombinant DNA molecules.

2. **Recall Historical Context**: The first artificial recombinant DNA molecules were constructed by scientists Stanley Cohen and Herbert Boyer.

3. **Understand the Process**: The construction of recombinant DNA involved the use of antibiotic resistance genes. These genes were crucial for selecting transformed cells that had successfully incorporated the recombinant DNA.

4. **Identify the Bacteria Used**: The two bacteria that were primarily used in this process were:
- **E. coli** (Escherichia coli)
- **Salmonella typhi**

5. **Select the Correct Option**: Among the given options, the correct pair of bacteria is E. coli and Salmonella typhi. This corresponds to option number four.

6. **Conclude the Answer**: Therefore, the answer to the question is that the pair of bacteria used during the construction of the first artificial recombinant DNA molecules is **E. coli and Salmonella typhi**.

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