Endangered plant species are conserved through

Options

A. Herbarium
B. Cryopreservation
C. Gene bank
D. Tissue culture.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the methods used to conserve endangered plant species.

2. **Identifying the Options**: The options provided are:
- Herbarium
- Cryopreservation
- Gene bank
- Tissue culture

3. **Analyzing Each Option**:
- **Herbarium**: This is a collection of preserved plant specimens used for research and education, but it does not actively conserve living plant species.
- **Cryopreservation**: This method involves freezing biological material at very low temperatures to preserve it, but it is not the primary method for conserving plant species.
- **Gene Bank**: This is a facility that stores genetic material from various plant species, preserving their genetic diversity and acting as a resource for future use.
- **Tissue Culture**: This technique involves growing plant cells in a controlled environment, which can be used for propagation but is not primarily a conservation method.

4. **Selecting the Correct Answer**: Among the options, the **Gene Bank** is the most effective method for conserving endangered plant species as it preserves genetic diversity and serves as a long-term repository.

5. **Conclusion**: Therefore, the correct answer is that endangered plant species are conserved through **Gene Banks**.