How many restriction endonuclease enzymes have been isolated till date from various bacteria?

Options

A. 200
B. 900
C. 1500
D. 1900

Answer

To answer the question of how many restriction endonuclease enzymes have been isolated from various bacteria, we can follow these steps:

### Step 1: Understand the Question
The question asks for the total number of restriction endonuclease enzymes that have been isolated from bacteria up to the present date.

### Step 2: Gather Information
From the provided information, we learn that a significant number of restriction enzymes have been identified. Specifically, the transcript mentions that a total of 900 restriction enzymes have been isolated.

### Step 3: Identify the Source
The transcript states that these 900 restriction enzymes have been isolated from approximately 230 different strains of bacteria. This indicates a diverse range of bacterial sources contributing to the total number of enzymes.

### Step 4: Evaluate the Options
The options provided in the question are:
1. 200
2. 900
3. 1500
4. 1900

From the information gathered, we can determine that the correct answer is option 2, which states that 900 restriction endonucleases have been isolated.

### Step 5: Conclude the Answer
Thus, the final answer to the question is that a total of **900 restriction endonuclease enzymes** have been isolated from various bacteria.

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