More advancement in genetic engineering is due to

Options

A. Restriction endonucleases
B. Reverse transcriptase
C. Protease
D. Zymase

Answer

### Step-by-Step Solution:

1. **Understanding Genetic Engineering**: Genetic engineering involves manipulating an organism's DNA to achieve desired traits. This field has advanced significantly due to various discoveries and tools.

2. **Discovery of Restriction Endonucleases**: The major advancement in genetic engineering is attributed to the discovery of restriction endonucleases. These enzymes act as "chemical scissors" that can cut DNA at specific sequences.

3. **Function of Restriction Endonucleases**: Before their discovery, it was challenging to cut DNA at precise locations. Restriction endonucleases enabled scientists to cut DNA either within the DNA strand or at the periphery, allowing for targeted manipulation of genetic material.

4. **Types of Nucleases**:
- **Exonucleases**: These enzymes remove nucleotides from the ends of DNA.
- **Endonucleases**: These enzymes cut the DNA strand at specific internal sites. Restriction endonucleases fall into this category.

5. **Importance of Restriction Enzymes**: The ability to cut DNA at specific sites revolutionized genetic engineering, allowing for the insertion, deletion, or modification of genes. This has led to advancements in various fields, including medicine, agriculture, and biotechnology.

6. **Other Enzymes**: While other enzymes like reverse transcriptase and proteases play roles in molecular biology, they are not primarily responsible for the advancements in genetic engineering like restriction endonucleases are.

7. **Conclusion**: Therefore, the correct answer to the question regarding the advancement in genetic engineering is the restriction enzyme.