The sticky ends generated by the action of Eco RI on insert DNA facilitate the action of which enzyme ?

Options

A. DNA polymerase
B. Taq polymerase
C. Alkaline phosphatase
D. DNA ligase

Answer

To answer the question regarding which enzyme is facilitated by the sticky ends generated by the action of Eco RI on insert DNA, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Eco RI**:
- Eco RI is a restriction enzyme that cuts DNA at specific sequences. It recognizes a particular palindromic sequence and makes cuts, resulting in the formation of sticky ends.

2. **Defining Sticky Ends**:
- Sticky ends are the overhanging ends of DNA that result from the uneven cuts made by restriction enzymes like Eco RI. These ends can easily anneal with complementary sequences.

3. **Role of Sticky Ends**:
- The sticky ends generated by Eco RI facilitate the joining of DNA fragments. This is crucial in recombinant DNA technology where different DNA pieces need to be joined together.

4. **Identifying the Enzyme**:
- The enzyme that acts on these sticky ends to join them together is DNA ligase. DNA ligase catalyzes the formation of phosphodiester bonds between the sticky ends, effectively sealing the DNA fragments together.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the sticky ends generated by Eco RI facilitate the action of DNA ligase.

### Final Answer:
The enzyme facilitated by the sticky ends generated by the action of Eco RI on insert DNA is **DNA ligase**.

---