Chapter 13: Biodiversity and Conservation

Biology • Class 12

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Chapter Analysis

Intermediate10 pages • English

Quick Summary

The chapter on Biodiversity and Conservation explains the significance of biodiversity at genetic, species, and ecosystem levels. It discusses patterns of biodiversity, reasons for its loss primarily due to human activities, and highlights the importance of conservation both in situ and ex situ. Additionally, the chapter emphasizes the ethical responsibility to preserve biodiversity for future generations and presents various methods and strategies for conservation.

Key Topics

  • Patterns of biodiversity
  • Causes of biodiversity loss
  • In situ and ex situ conservation
  • Human impact on biodiversity
  • Ethical and utilitarian values of biodiversity
  • Biodiversity hotspots
  • Species-area relationships
  • Ecological services provided by biodiversity

Learning Objectives

  • Understand the concept of biodiversity and its components.
  • Identify the patterns and distributions of biodiversity globally.
  • Recognize the causes and consequences of biodiversity loss.
  • Explore methods of biodiversity conservation and their significance.
  • Comprehend the ethical importance of preserving biodiversity.
  • Evaluate the impact of human activities on biodiversity.

Questions in Chapter

Name the three important components of biodiversity.

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How do ecologists estimate the total number of species present in the world?

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Give three hypotheses for explaining why tropics show greatest levels of species richness.

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What is the significance of the slope of regression in a species – area relationship?

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What are the major causes of species losses in a geographical region?

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How is biodiversity important for ecosystem functioning?

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What are sacred groves? What is their role in conservation?

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Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?

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The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?

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Can you think of a situation where we deliberately want to make a species extinct? How would you justify it?

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Additional Practice Questions

Define biodiversity and its components.

easy

Answer: Biodiversity is the sum total of diversity that exists at all levels of biological organisation. It is typically categorized into genetic diversity, species diversity, and ecosystem diversity.

Discuss the reasons why biodiversity is higher in tropical regions compared to polar regions.

medium

Answer: Biodiversity is higher in tropical regions due to several reasons: the tropics have had more evolutionary time without drastic climatic changes, they offer relatively stable environments which support niche specialization, and they have abundant solar energy which contributes to higher productivity.

Explain in situ and ex situ conservation methods with examples.

medium

Answer: In situ conservation involves protecting species in their natural habitat, such as in national parks or wildlife sanctuaries, like the Western Ghats. Ex situ conservation involves protecting species outside their natural environment, such as in zoos or seed banks.

What role do humans play in biodiversity loss, and how can they mitigate these effects?

hard

Answer: Humans contribute to biodiversity loss through habitat destruction, over-exploitation, pollution, and introducing invasive species. Mitigation can include enforcing legal protection of threatened habitats, promoting sustainable resource use, and raising awareness.

What is the importance of biodiversity to ecosystem resilience?

medium

Answer: Biodiversity enhances ecosystem resilience by providing robustness against disturbances, maintaining productivity, and offering a wider genetic pool that can adapt to changes.