In gentic engineering, DNA fragments are joined through

Options

A. Ligases
B. Polymerase
C. Helicase
D. Gyrase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the enzyme involved in joining DNA fragments in genetic engineering.

2. **Identifying the Options**: The options provided are:
- Ligases
- Polymerases
- Helicase
- Gyrase

3. **Analyzing Each Option**:
- **Ligases**: These are enzymes that join two DNA fragments together by forming phosphodiester bonds. This is crucial in genetic engineering for creating recombinant DNA.
- **Polymerases**: These enzymes are responsible for synthesizing new strands of DNA or RNA. They do not join fragments but rather create new strands.
- **Helicase**: This enzyme unwinds the DNA double helix during replication, allowing the strands to separate for copying.
- **Gyrase**: This enzyme alleviates the tension in the DNA strand that occurs during unwinding, preventing supercoiling.

4. **Selecting the Correct Answer**: Based on the analysis, ligases are the enzymes that specifically join DNA fragments together. Therefore, the correct answer is **Ligases**.

5. **Final Answer**: In genetic engineering, DNA fragments are joined through **Ligases**.

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