Which one of the following techniques made it possible to gnetically engineer living organisms ?

Options

A. Hybridization
B. Recombinant DNA techniques
C. X-ray diffraction
D. Heavier isotope labelling

Answer

**Step-by-Step Solution:**

1. **Understanding Genetic Engineering**: Genetic engineering involves altering the genetic material of an organism to achieve desired traits. This can be done through various techniques.

2. **Analyzing the Options**: The question provides four options:
- Hybridization
- Recombinant DNA techniques
- X-ray diffraction
- Heavier isotope labeling

3. **Evaluating Each Option**:
- **Hybridization**: This technique involves combining different varieties of organisms to produce hybrids. While it can lead to variations, it does not directly involve altering DNA at the molecular level.
- **Recombinant DNA Techniques**: This is a method that allows scientists to combine DNA from different sources. It involves cutting DNA molecules and inserting them into other DNA molecules, which is fundamental to genetic engineering.
- **X-ray Diffraction**: This technique is primarily used to study the structure of molecules, including DNA, but it does not facilitate genetic engineering.
- **Heavier Isotope Labeling**: This technique is used in various biochemical studies but does not play a role in the genetic engineering of organisms.

4. **Conclusion**: Among the options provided, the technique that directly enables the genetic engineering of living organisms is the **Recombinant DNA Techniques**.

**Final Answer**: Recombinant DNA techniques.

---