Which of the following has single stranded DNA

Options

A. `T_2 `phage
B. `T_4` phage
C. `phi xx 174`
D. `lamda` phage

Answer

To determine which of the given options has single-stranded DNA as its genetic material, we can analyze each option based on the information provided about their genetic structures.

### Step-by-Step Solution:

1. **Identify the Options**: The options given in the question are T2 phage, T4 phage, 5174 phage, and lambda phage.

2. **Analyze T2 Phage**:
- T2 phages are a type of bacteriophage, which are viruses that infect bacteria.
- The genetic material of T2 phages is double-stranded DNA (dsDNA).
- Conclusion: T2 phage does not have single-stranded DNA.

3. **Analyze T4 Phage**:
- T4 phages are also bacteriophages.
- Similar to T2, T4 phages have double-stranded DNA (dsDNA) as their genetic material.
- Conclusion: T4 phage does not have single-stranded DNA.

4. **Analyze 5174 Phage**:
- The 5174 phage is another type of bacteriophage.
- It is specifically mentioned that 5174 phages contain single-stranded DNA (ssDNA) as their genetic material.
- Conclusion: 5174 phage has single-stranded DNA.

5. **Analyze Lambda Phage**:
- Lambda phages are also bacteriophages.
- They have double-stranded DNA (dsDNA) as their genetic material.
- Conclusion: Lambda phage does not have single-stranded DNA.

6. **Final Conclusion**:
- Among the options provided, only the 5174 phage has single-stranded DNA as its genetic material. Therefore, the correct answer is option 3 (5174 phage).