Ch 12Biodiversity and its Conservation — Class 12 Zoology, concept-first.

Earth is home to an immense variety of living organisms -- plants, animals, and micro-organisms alike -- and it is this shared diversity of life that makes the planet such a remarkable place to live.

The 1992 UN Earth Summit defined biodiversity as the variability among living organisms from every source — terrestrial, marine and other aquatic ecosystems and the ecological complexes they belong to…

The term 'biodiversity' was coined by Walter Rosen in 1986, and it captures the idea that every species is finely adapted to live within a specific environment, so that biodiversity's distribution pat…

Edward Wilson popularised 'biodiversity' as covering every level of biological organisation, from individual populations up to entire biomes, and the chapter organises this into three levels (Fig.

Biodiversity is usually quantified as the number of species present in a region at a given time, and the current estimate for the whole planet is around 8-9 million species — though the true figure re…

Because organisms need a specific range of temperature, precipitation and other conditions for optimal growth and metabolism, and because those conditions are themselves set by latitude and altitude,…

The German naturalist and geographer Alexander von Humboldt, exploring the South American jungles, observed that within a region species richness increases as area increases, but only up to a certain…

Biodiversity is the variety of life on Earth — the number of different species of flora, fauna and micro-organisms that between them inhabit every kind of ecosystem, from rainforests and coral reefs t…

Using the international 'biome' classification system — based on climate, fauna, flora and soil conditions — India is divided into ten distinct biogeographic zones (Fig. 12.3).

Even though India ranks among the 17 identified mega-biodiverse countries in the world, it still faces substantial threats to its biodiversity.

Species have been evolving and going extinct ever since life first originated on Earth, but the rate at which species now disappear has accelerated sharply, destabilising both ecological stability and…

Hotspots are regions marked out by an unusually high concentration of endemic species that are simultaneously experiencing rapid habitat modification and loss.

A species classified as very likely to become extinct in the near future is termed an Endangered species.

A species is considered (globally) extinct once none of its members remain alive anywhere on Earth; if individuals survive only in captivity or under other human-controlled conditions, the species is…

The International Union for Conservation of Nature (IUCN), established in 1948 and headquartered in Gland, Switzerland, is an organisation dedicated to nature conservation and the sustainable use of n…

The 1972 Stockholm Declaration's guiding principle states that the Earth's natural resources — air, water, land, and the flora and fauna of its natural ecosystems — must be safeguarded for the benefit…

In-situ conservation is the conservation of genetic resources through their protection within the natural — or human-made — ecosystem in which they naturally occur; it protects an entire ecosystem and…

Ex-situ conservation is the conservation of selected rare plants and animals in locations outside their natural homes, and the chapter organises it into two broad approaches: offsite collections and g…

The World Wide Fund for Nature (WWF), founded in 1961 and headquartered in Gland, Vaud, Switzerland, is an international non-governmental charitable trust — formerly named the World Wildlife Fund — de…

The chapter illustrates habitat restoration through a real Indian case study: the Forestry Research Education and Extension Project (FREEP), a World Bank initiative operating in India, which employs a…

The Convention on Biological Diversity (CBD) — a United Nations initiative to protect biodiversity and encourage the sustainable use of natural resources — was adopted at the 1992 'Earth Summit' held…

This closing Evaluation exercise reviews the chapter's full span of biodiversity topics — the concept, levels, magnitude and patterns of biodiversity, its global and Indian importance, India's ten bio…

Sample papers and previous-year board questions for this subject.