The source of complementary RNA required for RNA silencing is

Options

A. infection by a virus having DNA genome
B. infection by a viroid having RNA genome
C. transposons which have copy and paste mechanism of transfer
D. transposons which have cut and paste mechanism of transfer

Answer

To solve the question "The source of complementary RNA required for RNA silencing is," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding RNA Silencing**:
- RNA silencing is a biological process that involves the regulation of gene expression. It is primarily used to inhibit the production of specific proteins by targeting their corresponding mRNA.

2. **Role of Complementary RNA**:
- In RNA silencing, complementary RNA is introduced to bind with the target mRNA. This binding prevents the mRNA from being translated into protein, effectively silencing the gene.

3. **Identifying the Source of Complementary RNA**:
- The complementary RNA required for RNA silencing can originate from various sources, but we need to identify the most relevant one in this context.

4. **Transposons as a Source**:
- Transposons, also known as "jumping genes," are segments of DNA that can move around within the genome. They can generate complementary RNA through their replication processes.

5. **Mechanism of Transposons**:
- Transposons can utilize a "copy and paste" mechanism to create RNA that is complementary to specific mRNA sequences. This complementary RNA can then participate in the silencing process.

6. **Evaluating Other Options**:
- Other potential sources mentioned in the question (like viruses or viroids) do not primarily serve as the source of the complementary RNA for RNA silencing in the same way that transposons do.

7. **Conclusion**:
- Based on the understanding of RNA silencing and the role of transposons, we conclude that the source of complementary RNA required for RNA silencing is indeed transposons.

### Final Answer:
The correct answer is **transposons**.

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