The importance of dicer enzyme in RNA interference technique is that it:

Options

A. causes degrasation of nematode m- RNA
B. silencing of RISC
C. cleaves dsRNA to siRNA
D. reduction in surface area of roots of host plants

Answer

### Step-by-Step Solution:

1. **Understanding RNA Interference (RNAi)**:
- RNA interference is a biological process in which RNA molecules inhibit gene expression or translation, effectively silencing targeted genes. This technique is particularly useful in combating diseases caused by pathogens, such as nematodes in plants.

**Hint**: RNA interference is a method used to silence specific genes in organisms.

2. **Role of Nematodes in Root Knot Disease**:
- Nematodes can inject their mRNA into plant cells, leading to the production of proteins that harm the plant by absorbing its nutrients. This results in root knot disease, which negatively affects plant health.

**Hint**: Nematodes cause damage by injecting their mRNA into plant cells.

3. **Introduction of Dicer Enzyme**:
- The Dicer enzyme plays a crucial role in the RNA interference technique. It is responsible for processing double-stranded RNA (dsRNA) into smaller fragments known as small interfering RNA (siRNA).

**Hint**: Dicer enzyme processes double-stranded RNA into smaller pieces.

4. **Function of Dicer Enzyme**:
- The primary function of the Dicer enzyme is to cleave the double-stranded RNA into small pieces, which are typically 20-25 nucleotides long. These siRNA molecules are then utilized by the RNA-induced silencing complex (RISC) to target and degrade the mRNA of the nematode.

**Hint**: Dicer enzyme converts dsRNA into siRNA that can target and degrade mRNA.

5. **Identifying the Correct Answer**:
- Among the options provided, the correct importance of the Dicer enzyme in RNA interference is that it cleaves double-stranded RNA to produce siRNA, which then leads to the degradation of the nematode mRNA, preventing the production of harmful proteins.

**Hint**: Look for the option that mentions Dicer's role in producing siRNA from dsRNA.

### Final Answer:
The importance of the Dicer enzyme in RNA interference technique is that it cleaves double-stranded RNA to siRNA, which leads to the degradation of nematode mRNA.