The enzymes responsible for restricting the growth of bacteriophage in Escherichia coli, is

Options

A. Added methyl group to protein
B. Cut DNA I particular fashion
C. Adden formuly group to DNA
D. Both (1) & (2)

Answer

To answer the question regarding the enzymes responsible for restricting the growth of bacteriophage in Escherichia coli, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding the Role of Enzymes in E. coli**:
- E. coli has specific enzymes that help protect it from bacteriophages, which are viruses that infect bacteria.

2. **Identifying the Enzymes**:
- The first enzyme mentioned is **methylase**, which adds methyl groups to certain DNA sequences. This modification helps the bacteria recognize its own DNA and distinguish it from foreign DNA, such as that from bacteriophages.
- The second enzyme is **restriction endonuclease**, which cuts DNA at specific sequences. This enzyme can recognize and cleave foreign DNA, thereby preventing the bacteriophage from replicating within the bacterial cell.

3. **Evaluating the Options**:
- The options provided include:
1. Adding a methyl group to the protein.
2. Cutting DNA in a particular fashion.
3. Adding a methyl group to the DNA.
4. Both one and two.
- Based on the definitions:
- Option 1 is partially correct but does not directly relate to bacteriophage restriction.
- Option 2 is correct as restriction endonucleases directly cut the DNA of bacteriophages.
- Option 3 is incorrect as it does not pertain to the restriction of bacteriophages.
- Option 4 combines the first two options, which includes the correct information.

4. **Conclusion**:
- The correct answer is **option 4**, as it encompasses both the action of methylase and restriction endonucleases, which together help restrict the growth of bacteriophages in E. coli.

### Final Answer:
The enzymes responsible for restricting the growth of bacteriophage in Escherichia coli are methylase and restriction endonucleases, making the correct answer **option 4**.