In biolistic method of gene trasfer, the microparticles coated with foreign DNA are bombarded into target cells at a very high velocity. These microparticles are made up of
1) silver or tungsten
2) arsenic or silver
3) gold or tungsten
4) none of these

Options

A. 1) silver or tungsten
B. 2) arsenic or silver
C. 3) gold or tungsten
D. 4) none of these

Explanation

To solve the question regarding the materials used in the biolistic method of gene transfer, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Biolistic Method**: The biolistic method, also known as the gene gun method, involves the use of microparticles that are coated with foreign DNA. These microparticles are then accelerated and shot into target cells at high velocities.

2. **Identify the Microparticles**: The question asks about the composition of these microparticles. It's important to know what materials are typically used in this method.

3. **Evaluate the Options**:
- **Option 1: Silver or Tungsten** - While tungsten is indeed used, silver is not typically used in this context.
- **Option 2: Arsenic or Silver** - Neither arsenic nor silver is used in the biolistic method.
- **Option 3: Gold or Tungsten** - This is a correct statement as both gold and tungsten are commonly used materials for the microparticles.
- **Option 4: None of these** - This option is incorrect since option 3 is valid.

4. **Select the Correct Answer**: Based on the evaluation, the correct answer is **Option 3: Gold or Tungsten**. These materials are effective for coating with foreign DNA and are used in the biolistic method of gene transfer.

### Final Answer:
The correct answer is **Option 3: Gold or Tungsten**.

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