Select the incorrect statement .

Options

A. More than 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 bacteriophage in Escherichia coli were isolated .
C. Some key tools recombinant DNA technology are restriction enzyme , polymerase enzyme , ligase , ligase , vectors and host root organisms.
D. EcoRl cut the DNA between bases A and T only when the sequence GAATTC is present in the DNA .

Answer

To solve the question, we need to evaluate each statement provided and identify the incorrect one. Here’s a step-by-step breakdown:

### Step 1: Analyze the statements

1. **Statement 1**: More than 900 restriction enzymes were isolated from 230 strains of bacteria.
- This statement is true. Since 1963, many restriction enzymes have been discovered, and it is accurate to say that over 900 have been isolated from various bacterial strains.

2. **Statement 2**: In 1963, two enzymes were responsible for restricting the growth of bacteriophage in E. coli. One added a methyl group to DNA, while the other cut the DNA sequence.
- This statement is also true. The two types of enzymes mentioned are indeed part of the restriction-modification system in bacteria, where one enzyme (methyltransferase) modifies the DNA, and the other (restriction endonuclease) cuts it.

3. **Statement 3**: Restriction Enzymes, Polymerase Enzymes, Ligase Enzymes, Vector Enzymes, Host Root Organisms are key tools for recombinant DNA technology.
- This statement is true. All these components play crucial roles in recombinant DNA technology.

4. **Statement 4**: E. coli cuts the DNA on the basis of Adenine and Thymine.
- This statement is incorrect. E. coli does not specifically cut DNA based solely on adenine and thymine. Instead, restriction enzymes like those from E. coli typically recognize specific sequences, such as GAA TTC, and cut between cytosine and guanine, not adenine and thymine.

### Conclusion
Based on the analysis, the incorrect statement is **Statement 4**.

### Final Answer
**The incorrect statement is Statement 4.**

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