(i) Biodiversity play a very important role in the shaping of nature at genetic, species and ecological levels. It has contributed in the development of human culture. It boosts ecosystem productivity where each species have an important role to play. A larger number of plant species means a greater variety of crops. Greater species diversity ensures natural sustainability for all life forms. There are mainly three roles of biodiversity.

*Ecological role of biodiversity: All species or organisms provide some kind of function to an ecosystem. They extract its needs from the ecosystem and at the same time contribute something useful for other organisms. Ecosystem helps in stabilization and moderation of the climate. Ecosystem with greater variety has more chance of stability.

*Economic role of biodiversity: Biodiversity is an important resource for daily life. Some of the important economic commodities provided by biodiversity are food crops, livestock, fish, medicinal resources etc. Pollinators, including bees and butterflies, provide significant environmental and economic benefits to agricultural and natural ecosystems, adding diversity and productivity to food crops.

*Scientific role of biodiversity: Biodiversity plays an important role in scientific studies as it helps us to understand, how the life evolved on the earth. It also helps in understanding the role of each species in sustaining ecosystems. The level of biodiversity is good indicator of the state of our relationships with other living species.

(ii) Biodiversity is the term popularised by the sociobiologist Edward Wilson. Biodiversity is also known as biological diversity. It refers to variety and variability of life on Earth. It includes microorganism, plants, animals and ecosystems such as coral reefs, forests, deserts. It is a measure of variation at the genetic, species and ecosystem level.

The factors that are responsible for the loss of biodiversity are:

*Hunting: It is one of the factors responsible for loss of biodiversity. Wild animals are hunted

For commercial utilization of their products such as hides and skin, tusk, fur, meat and decoration purposes.

*Pollution: It is a major threat to biodiversity. It is one of the difficult problems to overcome. It alters the natural habitat. Insecticides, pesticides, sulphur and nitrogen oxides, acid rain, ozone depletion and global warming affect adversely the plant and animal species.

*Habitat loss and fragmentation: A habitat is the place where a plant or animal naturally lives. The factors responsible for habitat loss are deforestation, fire and urbanization.

*Natural calamities: Natural calamities, such as floods, draught, forest fires, earthquakes, volcanic eruption etc destroy the biodiversity of different regions.

*Introduction of exotic species: Introduction of exotic species has caused widespread damage to natural biotic community in several parts of the world.

Steps needed to conserve biodiversity are:

*Endangered species should be preserved.

*Animals habitat should be protected and safeguarded where they feed, breed, rest and nurse their young ones.

*Proper planning and management should be done to prevent extinction.

*Preservation of varieties of plants, trees and animals.