The gold and tungsten particle are used for .

Options

A. Microinjection
B. Electroportatin
C. Calcium chloride treatment
D. Micro projectile bombardment

Answer

### Step-by-Step Solution

1. **Understanding the Question**: The question asks about the use of gold and tungsten particles in biotechnology.

2. **Identifying Methods of Gene Transfer**: There are various methods of gene transfer in biotechnology, including microinjection, electroporation, calcium chloride treatment, and microprojectile bombardment.

3. **Analyzing Each Method**:
- **Microinjection**: This method involves directly injecting DNA into the host cell using a microneedle or micropipette. Gold and tungsten particles are not used in this method.
- **Electroporation**: This technique creates temporary pores in the cell membrane using an electric field, allowing DNA to enter the cell. Gold and tungsten particles are not involved in this process.
- **Calcium Chloride Treatment**: This method also creates pores in the cell membrane to facilitate DNA entry. Again, gold and tungsten particles are not used here.
- **Microprojectile Bombardment**: Also known as the gene gun method, this technique involves coating DNA with gold or tungsten particles and then shooting them into the host cell at high velocity. This is the method where gold and tungsten are specifically utilized.

4. **Conclusion**: The correct answer to the question is that gold and tungsten particles are used for microprojectile bombardment.

### Final Answer
Gold and tungsten particles are used for microprojectile bombardment in biotechnology.

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