In the year `ul(X)` the two enzymes responsible for restricting the growth of bacteriophage in `ul(Y)` were isolated. One of these added methyl groups to DNA, while the other cut DNA.
Choose the option which correctly fills up the blands X and Y is

Options

A. X-1963,Y-Haemophilus influenzae
B. X-1963,Y-escherichia coli
C. X-1983,Y-Haemophilus influenzae
D. X-1983,Y-Echriachia coli

Answer

To solve the question, we need to identify the year and the organism related to the discovery of the two enzymes that restrict the growth of bacteriophages. These enzymes are known as restriction enzymes and methyltransferases.

### Step-by-Step Solution:

1. **Identify the Enzymes**: The question mentions two types of enzymes:
- One that adds methyl groups to DNA (methyltransferase).
- The other that cuts DNA (restriction endonuclease).

2. **Historical Context**: The discovery of restriction enzymes is attributed to the work done on bacteria, particularly in the context of their defense mechanisms against bacteriophages (viruses that infect bacteria).

3. **Year of Discovery**: The first restriction enzyme, EcoRI, was discovered in the early 1970s. The exact year often cited for the discovery of restriction enzymes is **1970**.

4. **Organism**: The restriction enzymes were first isolated from the bacterium **Escherichia coli** (E. coli).

5. **Fill in the Blanks**: Based on the above information:
- X = 1970
- Y = Escherichia coli (E. coli)

### Final Answer:
The correct option that fills the blanks is:
- X = 1970
- Y = Escherichia coli