Restriction endonuclease was isolated for the first time by W. Aber in 1962 in bacteria. Restriction endonucleases cut the DNA duplex at specific points therefore they are also called as molecular scissors or biological scissors. Three types of restriction endemicleases are Type 1. Type II and Type III but only Type II restriction endonucleases are used in recombinant DNA technology. Restriction endonuclease EcoR I recognises the base sequence GAATTC In DNA duplex and cut strands between G and A.
Restriction endonuclease was isolated for the first time from a:

Options

A. plant cell
B. animal cell
C. prokaryotic cell
D. germinal cell

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks from which type of cell restriction endonuclease was first isolated.

2. **Identifying the Source**: According to the information provided, restriction endonuclease was first isolated by W. Aber in 1962 from a specific bacterium.

3. **Recognizing the Bacterium**: The bacterium mentioned in the video transcript is *Haemophilus influenzae*.

4. **Classifying the Cell Type**: Since *Haemophilus influenzae* is a bacterium, it is classified as a prokaryotic cell. Prokaryotic cells are characterized by the absence of a nucleus and other membrane-bound organelles.

5. **Final Answer**: Therefore, the restriction endonuclease was isolated for the first time from a prokaryotic cell.