pBR322 has restriction sites for many restriction endonucleases. Which of these enzymes acting on pBR322 is not correctly matched with its source ?
I. Pvul : Providencia vulgaris.
II. Clal: caryophanon latum.
III. Sall : Streptomyces albus
IV. Pstl: Proteus stuarti

Options

A. I and II
B. II and IV
C. I and IV
D. II and III

Answer

To solve the question regarding the restriction sites of pBR322 and their corresponding sources, we will analyze each option step by step:

### Step 1: Analyze each enzyme-source match

1. **Pvul (Pvulgaris)**:
- The source of Pvul is actually **Proteus vulgaris**, not **Providencia vulgaris**. This is the first incorrect match.

2. **Clal (Caryophanon latum)**:
- The source of Clal is **Caryophanon latum**, which is correctly matched.

3. **Sall (Streptomyces albus)**:
- The source of Sall is **Streptomyces albus**, which is also correctly matched.

4. **Pstl (Proteus stuartii)**:
- The source of Pstl is **Proteus stuartii**, which is correctly matched.

### Step 2: Identify the incorrectly matched enzymes

From the analysis above, we can conclude that:
- **Pvul** is incorrectly matched with **Providencia vulgaris** instead of **Proteus vulgaris**.
- The other matches (Clal, Sall, and Pstl) are correctly matched.

### Final Conclusion:
The enzyme that is not correctly matched with its source is **Pvul: Providencia vulgaris**.

### Answer:
The answer is **I. Pvul: Providencia vulgaris**.

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