Biodiversity refers to the combined diversity at all levels of biological organisation. It includes genetic diversity, species diversity and ecological diversity.
Importance of biodiversity: (i) A wide range of materials such as fibres, dyes, resins are obtained from plants. (ii) A variety of plants and animals are utilised as sources of food. (iii) Medicinal plants act as sources of drugs. (iv) Plants and animals also have a cultural and aesthetic value.