Which of the following is/are part of biotechnology?
A. Correcting a defective gene .
B.Developing a DNA vaccine
C. In vitro fertilisation
D.Synthesis of a gene.

Options

A. A,B
B. B,C
C. C,D
D. A,B,C,D

Answer

To determine which of the options are part of biotechnology, we can analyze each option based on the principles and applications of biotechnology.

### Step-by-Step Solution:

1. **Understanding Biotechnology**:
- Biotechnology involves using living organisms or their products to develop or create useful products for humans. This can include genetic manipulation, cell culture, and other techniques.

2. **Analyzing Option A - Correcting a defective gene**:
- This is a key application of biotechnology. Techniques such as recombinant DNA technology allow scientists to correct genetic defects by altering the DNA sequence.
- **Conclusion**: This is part of biotechnology.

3. **Analyzing Option B - Developing a DNA vaccine**:
- DNA vaccines are a form of biotechnology where DNA is used to elicit an immune response. They are developed using biotechnological methods to create vaccines that can protect against diseases.
- **Conclusion**: This is part of biotechnology.

4. **Analyzing Option C - In vitro fertilisation**:
- In vitro fertilization (IVF) is a process where eggs and sperm are combined outside the body to create embryos. This technique is widely used in reproductive biotechnology.
- **Conclusion**: This is part of biotechnology.

5. **Analyzing Option D - Synthesis of a gene**:
- The synthesis of genes involves creating DNA sequences in the laboratory, which is a fundamental aspect of biotechnology. This can be used for various applications, including gene therapy and research.
- **Conclusion**: This is part of biotechnology.

6. **Final Conclusion**:
- Since all options A, B, C, and D are indeed part of biotechnology, the correct answer is that all of them are included.

### Final Answer:
All of the options (A, B, C, D) are part of biotechnology.

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