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Loss of Biodiversity — Revision Notes

ICSE · Class 11 · Geography

Loss of Biodiversity revision notes for ICSE Class 11 Geography: 4 topics in quick points. Part of the ICSE Class 11 Geography syllabus.

64 questions28 flashcards5 concepts

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Key Topics to Revise

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1. Meaning and Importance of Biodiversity Loss

  • Biodiversity loss is the shrinkage of species numbers and the degradation of their habitats.
  • Fast population growth and improvement in living conditions have increased pressure on natural resources.
  • Overpopulation and biodiversity loss have caused major damage in tropical regions.
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2. Types of Species in Loss of Biodiversity

  • From the viewpoint of loss of biodiversity, species are divided into three main classes: threatened, endangered, and extinct.
  • Threatened species are those whose lives are at risk.
  • WCMC's Red Data Books mention 66,000 plant and 2,000 animal species threatened worldwide.
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3. Geological Extinction Episodes

  • There are six recognised geological extinction episodes in Earth's history.
  • These episodes are Ordovician, Devonian, Permian, Triassic, Cretaceous, and Pleistocene.
  • Ordovician extinction occurred 500 million years ago and eliminated about 50% of animal families, including several trilobites.
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4. Causes of Extinction of Species

  • Habitat destruction is a major cause of species extinction.
  • Growing human population and modern activities are the main reasons for habitat destruction.
  • In 49 out of 61 old world tropical countries, more than 50% of wildlife habitat has been destroyed.

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Full Notes

Key Concepts

Biodiversity loss is the reductionThreatened species are species whose livesEndangered species are species that faceA species is extinct when noSix major extinction episodes are recognised

Frequently Asked Questions

What are the important topics in Loss of Biodiversity for ICSE Class 11 Geography?
Key topics in Loss of Biodiversity include Meaning and Importance of Biodiversity Loss, Types of Species in Loss of Biodiversity, Geological Extinction Episodes, Causes of Extinction of Species. Study these first, then practise questions on each for Class 11 exams.
How should I revise Loss of Biodiversity for Class 11 exams?
Learn the core ideas first, then work through the 64 practice questions on Loss of Biodiversity. Revise definitions regularly and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

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