Recombinant DNA bearing ampicillin resistance gene is passed in E. coli. The latter are spread on agar plates containing ampicillin. Then

Options

A. Both transformed and untransformed cells die
B. Both transformed and untransformed cells grow
C. Transformed recipient cells grow and untransformed cells die
D. Transformed recipient cells die and untransformed cells grow.

Answer

To solve the question regarding the effect of recombinant DNA bearing an ampicillin resistance gene on E. coli when spread on agar plates containing ampicillin, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**:
- We start with E. coli bacteria that have been transformed with recombinant DNA containing an ampicillin resistance gene.

2. **Transformation Process**:
- The process of transformation allows E. coli to take up the recombinant DNA, which gives them the ability to resist the antibiotic ampicillin.

3. **Agar Plate Preparation**:
- The transformed E. coli are then spread on agar plates that contain ampicillin.

4. **Effect of Ampicillin**:
- Ampicillin is an antibiotic that kills bacteria that do not have resistance to it.
- Transformed E. coli (those that have taken up the resistance gene) will be able to survive in the presence of ampicillin.

5. **Differentiating Transformed and Untransformed Cells**:
- Transformed cells will grow on the agar plates because they can resist the effects of ampicillin.
- Untransformed cells, which lack the resistance gene, will not survive in the presence of ampicillin and will die.

6. **Conclusion**:
- Therefore, the outcome of spreading the transformed E. coli on agar plates containing ampicillin is that the transformed recipient cells grow, while the untransformed cells die.

### Final Answer:
The correct answer is: **Transformed recipient cells grow and untransformed cells die.**

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