Biodiversity is the variety in the various life forms. It is related to all living plants, animals, and microbes found in their natural habitats. There are more than 20,000 species of ants, 3,00,000 species of beetles, 28,000 species of fishes and nearly 20,000 species of orchids.
So, the correct answer is 'Living plants, animals and microbes found in their natural habitats'.