In the process of transformation, divalent ions are used to make the host component. The function of such ions is to

Options

A. increase the efficiency of DNA entering the bacterium
B. make the DNA hydrophobic so that it enters the bacterium
C. force the DNA inside the bacterium by applying heat
D. break the DNA into smaller fragments for better uptake into the bacterium

Answer

To solve the question regarding the function of divalent ions in the process of transformation, we can break it down into several steps:

### Step-by-Step Solution:

1. **Understanding Transformation**:
- Transformation is the process by which a bacterium takes up foreign DNA from its environment. This is a key method used in genetic engineering.

2. **Role of Divalent Ions**:
- Divalent ions, such as calcium ions (Ca²⁺), are used to facilitate the transformation process. These ions play a crucial role in making the bacterial cell membrane more permeable.

3. **Mechanism of Action**:
- When bacteria are treated with a solution containing divalent ions, the ions interact with the cell membrane. This interaction increases the permeability of the membrane, allowing DNA to enter the cell more easily.

4. **Chemical Competence**:
- The presence of divalent ions helps in making the bacterial cells "chemically competent." This means that the cells are more capable of taking up DNA from their surroundings.

5. **Heat Shock Treatment**:
- After the bacteria are exposed to divalent ions, a heat shock treatment is often applied. This sudden increase in temperature creates a thermal imbalance that further facilitates the uptake of DNA.

6. **Conclusion**:
- Therefore, the primary function of divalent ions in the transformation process is to increase the efficiency of DNA entering the bacterium.

### Final Answer:
The function of such ions is to **increase the efficiency of DNA entering the bacterium**.

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