Preserving Genetic Diversity in a Gene Sanctuary

In a gene sanctuary, the preservation of genetic diversity of an endangered species can be achieved by protecting the ecosystem in which that species occurs naturally. This option, mentioned as option 'A', is the correct answer.

Explanation:

1. Protecting the Ecosystem
One of the key aspects of preserving genetic diversity is to protect the natural ecosystem in which the endangered species resides. This includes conserving the habitat, maintaining the balance of the ecosystem, and preventing any disruption or destruction of the natural environment. By safeguarding the ecosystem, all the different factors that contribute to genetic diversity, such as climatic conditions, food availability, and interactions with other species, are also preserved.

2. Importance of Ecosystem
The ecosystem plays a crucial role in the survival and evolution of a species. It provides a diverse range of habitats and niches, allowing for the development of various adaptations and genetic traits. When the ecosystem is conserved, it ensures the continuity of natural selection processes, allowing the species to adapt and evolve over time. This leads to the maintenance of genetic diversity within the population, which is essential for its long-term survival.

3. Genetic Variation
Genetic diversity refers to the variety of genes and alleles present within a population. It is crucial for the overall health and resilience of a species. Genetic variation allows for adaptation to changing environmental conditions, resistance to diseases, and the ability to cope with other challenges. In the absence of genetic diversity, a population becomes more susceptible to genetic disorders, reduced fertility, and decreased adaptability, which can ultimately lead to extinction.

4. Alternatives
Preserving DNA samples of different varieties in a laboratory and growing them under controlled conditions, as mentioned in option 'B', may help in conserving genetic material, but it does not ensure the preservation of genetic diversity in the natural population. It lacks the dynamic processes of natural selection and interaction with the environment that contribute to genetic diversity.

Conclusion
In conclusion, protecting the ecosystem in which an endangered species occurs naturally is the most effective way to preserve its genetic diversity. By conserving the natural habitat, all the essential factors for genetic variation and adaptation are maintained, ensuring the long-term survival of the species.