Select the incorrect statement .

Options

A. Unto 900 restriction enzymes have been isolated from over 230 strains of bacteria.
B. In the year 1963 , the two enzymes responsible for restricting the growth of bacteriopage in Escherichia coli were isolated.
C. Polymerase enzyme is one of the key tools for recombinant DNA technology.
D. EcoRI cut the DNA between bases G and A producing blunt ends, when te sequence GAATTC is present in the DNA.

Answer

To solve the question, we need to analyze each statement provided and identify the incorrect one. Let's break it down step by step.

### Step 1: Analyze Statement 1
**Statement 1:** Up to 900 restriction enzymes have been isolated from over 230 strains of bacteria.

- **Analysis:** This statement is true. There are indeed over 900 restriction enzymes that have been identified, and they are derived from various strains of bacteria.

### Step 2: Analyze Statement 2
**Statement 2:** In the year 1963, two enzymes which are responsible for restricting the growth of bacteriophage were isolated from E. coli bacteria.

- **Analysis:** This statement is also true. The discovery of restriction enzymes in E. coli was indeed made around 1963, and these enzymes serve to protect bacteria from bacteriophages.

### Step 3: Analyze Statement 3
**Statement 3:** Polymerase enzyme is one of the key tools for recombinant DNA technology.

- **Analysis:** This statement is true. DNA polymerases are essential in recombinant DNA technology for synthesizing new DNA strands.

### Step 4: Analyze Statement 4
**Statement 4:** Eco-R1 cuts the DNA between the bases G and A producing blunt ends when the sequence GAATCC is present in the DNA.

- **Analysis:** This statement is incorrect. EcoRI does cut the DNA between G and A in the sequence GAATTC, but it produces sticky ends, not blunt ends. Blunt ends are produced by different restriction enzymes.

### Conclusion
The incorrect statement is **Statement 4**.

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