Which one of the following is not a site for in-situ method of conservation of flora?

The correct answer is B. A botanical garden is an ex-situ site: plants are taken out of their natural habitat and grown in a controlled setting, such as living collections, arboreta and seed banks. In-situ conservation means protecting species where they naturally occur, so the habitat itself stays intact.

The other three are in-situ sites:

• Biosphere Reserve: a UNESCO MAB concept with core, buffer and transition zones, where the natural ecosystem is protected and used sustainably.
• National Park: a legally protected area under the Wildlife (Protection) Act, 1972, where human activity is largely prohibited.
• Wildlife Sanctuary: also under the 1972 Act, with fewer restrictions than a national park, protecting the habitat of flora and fauna.

Core concept: in-situ versus ex-situ conservation, as framed in Article 8 and Article 9 of the Convention on Biological Diversity. This links to Mains GS-III on biodiversity, the Biological Diversity Act, 2002, and habitat protection.

Trap: many aspirants mark the botanical garden as a protected area because it is green and managed. Ask the test question: is the species protected in its natural home? If not, it is ex-situ.