The biological scissors are :
i. Restriction enzymes are used to cut DNA into nucleotide monomers.
ii. Enzymes always cut the DNA at specific nucleotide sequences.
iii. Present variously recognizing and cutting different DNA sequences.
Select the option with the correct statement/s.

Options

A. i and ii
B. ii and iii
C. i and iii
D. i, ii and iii

Answer

To solve the question regarding the statements about biological scissors (restriction enzymes), we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding Biological Scissors**:
- Biological scissors refer to restriction enzymes, which are used in biotechnology for cutting DNA at specific locations.

2. **Analyzing Statement i**:
- Statement i claims: "Restriction enzymes are used to cut DNA into nucleotide monomers."
- **Evaluation**: This statement is incorrect. Restriction enzymes do not cut DNA into individual nucleotides (monomers). Instead, they cut DNA at specific sites to create fragments containing multiple nucleotides, which can include entire genes or other functional DNA segments.

3. **Analyzing Statement ii**:
- Statement ii claims: "Enzymes always cut the DNA at specific nucleotide sequences."
- **Evaluation**: This statement is correct. Each restriction enzyme recognizes a specific sequence of nucleotides and cuts at that precise location. This specificity is crucial for genetic engineering and molecular cloning.

4. **Analyzing Statement iii**:
- Statement iii claims: "Present variously recognizing and cutting different DNA sequences."
- **Evaluation**: This statement is also correct. There are many different restriction enzymes, each with its own recognition sequence, allowing them to cut DNA at various specific sites.

5. **Conclusion**:
- Based on the evaluations:
- Statement i is incorrect.
- Statements ii and iii are correct.
- Therefore, the correct answer is that statements ii and iii are true.

### Final Answer:
The correct statements are: **ii and iii**.