Source: NCERT Official Textbook
The chapter breaks down biodiversity into three hierarchical levels: Genetic Diversity (variation of genes within a species), Species Diversity (the variety of species in an area), and Ecosystem Diversity (the diversity of habitats and ecological processes).
It elaborates on the critical roles biodiversity plays: an Ecological Role (maintaining ecosystem functions like nutrient cycling and climate regulation), an Economic Role (as a reservoir of resources for food, medicine, and materials), and a Scientific Role (providing clues about evolution and life’s functioning).
The second half addresses the alarming Loss of Biodiversity, citing causes like human overpopulation, overexploitation, deforestation, natural calamities, pollution, and the introduction of exotic species. The IUCN’s classification of threatened species into Endangered, Vulnerable, and Rare categories is explained.
The chapter concludes with the Conservation of Biodiversity, stressing the need for sustainable development, community involvement, and international cooperation, referencing the Earth Summit (1992) and the Convention on Biodiversity.
It introduces the concepts of mega-diversity countries and biodiversity hotspots—areas with high species richness facing severe threats—and highlights legal frameworks like India’s Wild Life (Protection) Act, 1972, for establishing protected areas.
Biodiversity is consistently richer in which regions? (Pg. 2)
What does Genetic Diversity refer to? (Pg. 2)
Areas rich in species diversity are called: (Pg. 3)
Which role of biodiversity includes the concept of ‘crop diversity’ or agro-biodiversity? (Pg. 3)
According to the chapter, what is our ethical responsibility towards other species? (Pg. 4)
Species which are not natural inhabitants but are introduced into a local habitat are called: (Pg. 4)
The Convention on Biodiversity was signed at the Earth Summit in 1992 in: (Pg. 5)
(Exercise) Conservation of biodiversity is important for: (Pg. 6)
(Exercise) Threatened species are those which: (Pg. 6)
(Exercise) National parks and sanctuaries are established for the purpose of: (Pg. 6)
(Exercise) Biodiversity is richer in: (Pg. 7)
(Exercise) In which country was the ‘Earth Summit’ held? (Pg. 7)
Biodiversity is a combination of two words: Bio (life) and ______ (variety). (Pg. 2) Page 115
Groups of individual organisms having certain similarities in their physical characteristics are called ______. (Pg. 2) Page 115
The broad differences between ecosystem types and the diversity of habitats constitute ______ diversity. (Pg. 3) Page 116
Species capture and store energy, produce and decompose organic materials, and help cycle water and nutrients, fulfilling the ______ role of biodiversity. (Pg. 3) Page 116
The International Union for Conservation of Nature publishes the ______ List of threatened species. (Pg. 4) Page 117
The IUCN classifies threatened species into three categories: Endangered, Vulnerable, and ______ Species. (Pg. 4) Page 117
Countries situated in tropical regions that possess a large number of the world’s species are called ______ centres. (Pg. 5) Page 118
(Exercise) The different levels of biodiversity are genetic, species, and ______. (Pg. 7) Page 120
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