NCERT Notes: Biodiversity [Geography Notes For UPSC]

NCERT notes on important topics for the UPSC civil services exam. These notes will also be useful for other competitive exams like banking PO, SSC, state civil services exams and so on. This article talks about biodiversity.



  • Biodiversity itself is a combination of two words, Bio (life) and diversity (variety).
  • It is the number and variety of organisms found within a specified topographical region.
  • It brings up to the varieties of flora, fauna, and micro-organisms, the genes they contain and the ecosystems they form.
  • It relates to the variability among living organisms on the earth, including the variability within and between the species and that within and between the ecosystems.
  • Biodiversity is an arrangement in continuous evolution, from the viewpoint of an individual organism as well as from a viewpoint of species.
  • It is not found uniformly on the earth.

Biodiversity Types


Biodiversity can be discussed at three levels:
  • Genetic diversity
  • Species diversity
  • Ecosystem diversity

Genetic Diversity
  • Genetic biodiversity refers to the variation of genes within species.
  • Genes are the basic building blocks of several life forms.
  • Species are the groups of individual organisms having definite resemblances in their physical characteristics.
  • Human beings inherently belong to the Homo sapiens group.
  • They also differ in their features such as physical appearance, height, etc. This is due to genetic diversity.
  • This genetic diversity is vital for healthy breeding of population of species.

Species Diversity
  • Species Diversity refers to the variety of species.
  • It relates to the number of species in a demarcated area.
  • The diversity of species can be measured through its abundance, richness, and types.
  • The regions rich in species diversity are called hotspots of diversity.


Ecosystem Diversity
  • The wide differences between types of ecosystem and the diversity of habitats and ecological processes happening inside each ecosystem type set up the ecosystem diversity.
  • The boundaries of communities and ecosystems are not very strictly demarcated.
  • Hence the demarcation of ecosystem boundaries is intricate and difficult.

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