One of the most important functions of botanical gardens is that

Options

A. One can observe tropical plants there
B. They allow ex situ conservation of germplasm
C. They provide the natural habitat for wildlife
D. They provide a beautiful area for recreation

Answer

### Step-by-Step Solution:

1. **Understanding Botanical Gardens**:
- Botanical gardens are specialized gardens where a variety of plants are cultivated for scientific, educational, and recreational purposes. They play a significant role in the conservation of plant diversity.

2. **Functions of Botanical Gardens**:
- One of the primary functions of botanical gardens is to facilitate **ex-situ conservation**. This means that plants are grown outside their natural habitats, which helps in preserving plant species that may be threatened or endangered in the wild.

3. **Ex-situ Conservation Explained**:
- Ex-situ conservation involves taking plants from their natural environment and cultivating them in controlled settings, such as botanical gardens. This can include the preservation of whole plants or their germplasm (seeds, spores, or other plant tissues).

4. **Evaluating Other Options**:
- While botanical gardens do allow for the observation of various plant species, including tropical plants, they are not limited to just tropical plants.
- Botanical gardens do not provide natural habitats for wildlife since they are designed for the cultivation of plants rather than for wildlife conservation.
- Although botanical gardens may be aesthetically pleasing, they are not primarily recreational spaces where human activities are encouraged.

5. **Conclusion**:
- Based on the functions of botanical gardens, the most important function is that they allow for the **ex-situ conservation of germplasm** of plants. Therefore, the correct answer is option B.