Pick the odd one out:

Options

A. DNA microinjection
B. RNA interference
C. Retro virus mediated gene transfer
D. Embryonic stem cell mediated gene transfer

Answer

**Step-by-Step Solution:**

1. **Identify the Options:**
- The options given are:
1. DNA microinjection
2. RNA interference
3. Retrovirus mediated gene transfer
4. Embryonic stem cell mediated gene transfer

2. **Analyze Each Option:**
- **DNA Microinjection:** This is a method of introducing a transgene into the pronucleus of a zygote using a micropipette. It is a direct method of gene transfer.
- **RNA Interference:** This is a molecular process that suppresses gene expression using double-stranded RNA. It does not involve the introduction of a gene but rather the regulation of gene expression.
- **Retrovirus Mediated Gene Transfer:** This method uses retroviruses as vectors to deliver a transgene into host cells. It is commonly used in gene therapy.
- **Embryonic Stem Cell Mediated Gene Transfer:** This method involves introducing DNA into embryonic stem cells, similar to retrovirus-mediated transfer.

3. **Compare the Options:**
- The first, third, and fourth options (DNA microinjection, retrovirus mediated gene transfer, and embryonic stem cell mediated gene transfer) are all methods of gene transfer that involve the introduction of a gene into a cell.
- The second option (RNA interference) is fundamentally different as it involves suppressing gene expression rather than transferring a gene.

4. **Identify the Odd One Out:**
- Since RNA interference does not involve the transfer of a gene but rather the suppression of gene expression, it is the odd one out among the options.

**Final Answer:**
The odd one out is **RNA interference**.

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