To which of the following techniques would you associ- ate the phenomenon of insertional inactivation?

Options

A. Southern blotting
B. Northern blotting
C. Selection of recombinants
D. Microprojection

Answer

**Step-by-Step Solution:**

1. **Understanding Insertional Inactivation**: Insertional inactivation refers to the phenomenon where the insertion of a foreign DNA fragment into a gene disrupts its function. This is commonly observed in recombinant DNA technology.

2. **Identifying the Context**: In the context of the question, we need to determine which technique is associated with insertional inactivation. The options provided are Southern blotting, Northern blotting, selection of recombinants, and microprojection.

3. **Analyzing the Options**:
- **Southern Blotting**: This technique is used for detecting specific DNA sequences. It does not involve the insertion of foreign DNA into a gene.
- **Northern Blotting**: This technique is used for detecting specific RNA sequences. Similar to Southern blotting, it does not involve insertional inactivation.
- **Selection of Recombinants**: This technique is directly related to recombinant DNA technology. It involves inserting foreign DNA into a plasmid, which can lead to the inactivation of a gene (e.g., an antibiotic resistance gene). If the gene becomes non-functional due to the insertion, the bacteria will not survive in the presence of the antibiotic.
- **Microprojection**: This technique is not commonly associated with insertional inactivation.

4. **Conclusion**: The correct technique associated with the phenomenon of insertional inactivation is the **selection of recombinants**. This technique allows for the identification of bacteria that have successfully taken up recombinant plasmids by observing their growth in the presence of antibiotics.

**Final Answer**: Selection of recombinants.

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