Restriction endonucleases are enzymes which

Options

A. Make cuts at specific positions within the DNA molecule
B. Recognise a specific nucleotide sequence for binding of DNA ligase
C. Restrict the action of the enzyme DNA polymeras
D. Remove nucleotides from the ends of the DNA molecule

Answer

**Step-by-Step Text Solution:**

1. **Understanding Restriction Endonucleases**:
- Restriction endonucleases are enzymes that play a crucial role in molecular biology. They are known for their ability to cut DNA at specific locations.

2. **Function of Restriction Endonucleases**:
- These enzymes recognize specific sequences of nucleotides in the DNA, known as restriction sites, and make cuts at or near these sites. This is essential for various biological processes, including the defense mechanism against bacteriophages (viruses that infect bacteria).

3. **Importance in Biotechnology**:
- Restriction endonucleases are vital tools in recombinant DNA technology. They allow scientists to manipulate DNA by cutting it into fragments, which can then be recombined in various ways for research, therapeutic, or agricultural purposes.

4. **Evaluating the Options**:
- **Option A**: "Make cut at specific position within the DNA molecule." - This is correct as it describes the primary function of restriction endonucleases.
- **Option B**: "Recognize a specific nucleotide sequence for binding of DNA ligase." - This is incorrect; while restriction enzymes recognize specific sequences, they do not bind DNA ligase.
- **Option C**: "Restrict the action of the enzyme DNA polymerase." - This is incorrect; restriction endonucleases do not restrict DNA polymerase.
- **Option D**: "Remove nucleotide from the ends of DNA molecule." - This is also incorrect; this describes the action of exonucleases, not endonucleases.

5. **Conclusion**:
- Based on the evaluation, the correct answer is **Option A**: "Make cut at specific position within the DNA molecule."