Restricito enzymes cut the strand of DNA a little away from the centre of the palindromic site, but between the same two bases on the opposite single stranded strand, these overhanging stretches formed on each strand are called __________

Options

A. Blunt ends
B. Stickly ends
C. Staggered end
D. Both (2) & (3)

Answer

To answer the question regarding the overhanging stretches formed by restriction enzymes, follow these steps:

### Step-by-Step Solution:

1. **Understanding Restriction Enzymes**:
- Restriction enzymes are proteins that cut DNA at specific sequences known as restriction sites. These sites are often palindromic, meaning the sequence reads the same forwards and backwards on complementary strands.

2. **Identifying the Cut**:
- When a restriction enzyme, such as EcoR1, recognizes a palindromic sequence, it cuts the DNA at a specific location. For example, EcoR1 cuts the sequence between the bases G and A in the sequence 5' - GaATTC - 3'.

3. **Formation of Overhangs**:
- The cut made by the restriction enzyme does not occur directly in the center of the palindromic site but rather a little away from it. This results in the formation of overhanging ends on both strands of DNA.

4. **Defining the Overhanging Structures**:
- The overhanging stretches that are formed on each strand after the cut are known as "sticky ends." These sticky ends are capable of base pairing with complementary sequences, making them useful in various molecular biology applications.

5. **Conclusion**:
- Therefore, the answer to the question is that the overhanging stretches formed on each strand by the action of restriction enzymes are called "sticky ends."

### Final Answer:
The overhanging stretches formed on each strand by restriction enzymes are called **sticky ends**.