Using imprints from a plate with complete medium and carrying bacterial colonies, you can select streptomycin-resistant mutants and prove that such mutations do not originates as adaptation. These imprints need to be used

Options

A. On plates with and without streptomycin
B. Only on plates with streptomycin
C. On plates with minimal medium
D. Only on plates without streptomycin

Answer

To solve the question regarding the selection of streptomycin-resistant mutants using imprints from a plate with complete medium carrying bacterial colonies, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Purpose of the Experiment**:
- The goal is to select streptomycin-resistant mutants from a bacterial population and demonstrate that these mutations do not arise as adaptations to the antibiotic.

2. **Identifying the Types of Plates**:
- We have different types of plates to consider:
- Plates with streptomycin (antibiotic).
- Plates without streptomycin.
- Plates with minimal medium (which may not support all bacterial growth).
- Plates with complete medium (which supports all bacterial growth).

3. **Analyzing Growth Conditions**:
- **Plates with streptomycin**: Only bacteria that are resistant to streptomycin can grow.
- **Plates without streptomycin**: Both resistant and non-resistant bacteria can grow.
- **Plates with minimal medium**: This may limit growth to only certain bacteria, depending on their nutritional requirements.
- **Plates with complete medium**: This supports the growth of all bacteria but does not help in selecting for resistance.

4. **Selecting the Appropriate Plates for Imprints**:
- To select streptomycin-resistant mutants effectively, imprints should be made on plates that contain streptomycin. This ensures that only the resistant mutants will grow and can be identified.
- Using plates without streptomycin would not be effective, as both resistant and non-resistant bacteria would grow, making it impossible to distinguish the mutants.

5. **Conclusion**:
- The best choice for making imprints to select streptomycin-resistant mutants is to use plates that contain streptomycin (option number 2). This allows for the propagation of only those bacteria that are resistant to the antibiotic.

### Final Answer:
The imprints need to be used on plates with streptomycin (option number 2).

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