Chapter 15: Biodiversity and Conservation Class 12 Biology NCERT Solutions

Learn the significance of biodiversity, threats, and conservation strategies with Chapter 15 NCERT Solutions. Download free PDFs for smart revision. Scroll below for full chapter solutions.

What You Will Learn in Chapter 15 – Biodiversity and Conservation

This chapter introduces students to the richness of life on Earth, covering different types of biodiversity and conservation strategies. It also includes national and global efforts to prevent biodiversity loss.

Key Topics Covered:

1. Biodiversity: Definition and Types

  • Biodiversity refers to the variety of life forms found on Earth.

  • Three levels of biodiversity:

    • Genetic diversity: Variety of genes within species.

    • Species diversity: Variety of species in a given region.

    • Ecological diversity: Variety of ecosystems like forests, deserts, wetlands, etc.

2. Biodiversity in India

  • India is one of the 12 mega-diverse countries in the world.

  • Hotspots of biodiversity in India: Western Ghats, Himalayas, Indo-Burma, and Sundaland.

  • High species richness and endemism in India.

3. Patterns of Biodiversity

  • Latitudinal gradient: Biodiversity increases from the poles to the equator.

  • Species-area relationship: Greater the area, higher the number of species.

  • Described by Alexander von Humboldt through a mathematical model.

4. Importance of Biodiversity

  • Ecological role: Maintains ecosystem functions and stability.

  • Economic value: Provides food, fuel, fiber, medicine, and ecosystem services.

  • Ethical and aesthetic values: Respect for all forms of life; inspiration, culture, and heritage.

5. Loss of Biodiversity

  • Major causes of biodiversity loss (HIPPO):

    • H: Habitat loss and fragmentation.

    • I: Invasive species.

    • P: Pollution.

    • P: Population explosion (human).

    • O: Overexploitation of resources.

  • Extinction of species and ecosystem imbalance.

6. Biodiversity Conservation

  • In Situ Conservation:

    • Protecting species in their natural habitat.

    • Includes biosphere reserves, national parks, wildlife sanctuaries, and sacred groves.

  • Ex Situ Conservation:

    • Protecting species outside their natural habitat.

    • Includes zoos, botanical gardens, seed banks, cryopreservation.

7. Global Efforts for Conservation

  • IUCN Red List: Categorizes species based on extinction risk.

  • Convention on Biological Diversity (CBD): International treaty to conserve and share genetic resources.

  • Earth Summit (1992), Rio de Janeiro: Promoted sustainable development and conservation.

Why Use Our NCERT Solutions for Chapter 15?

Our detailed and student-friendly solutions for Chapter 15: Biodiversity and Conservation help simplify complex environmental concepts and enhance understanding with diagrams and real-world examples. These solutions are designed for effective exam preparation and concept clarity.

Highlights of Our Solutions:

  • All NCERT Intext and Exercise questions answered in a simple, precise manner.

  • Definitions, examples, and significance of different levels of biodiversity.

  • Diagrams to explain species-area relationships and conservation models.

  • Practical examples of biodiversity conservation in India and globally.

  • Perfect for CBSE Board, NEET, and other entrance exam preparation.

NCERT Solutions for Chapter 15 – Biodiversity and Conservation

Intext Questions:

  • Detailed explanations of the three levels of biodiversity.

  • Examples and significance of Indian biodiversity hotspots.

  • Real-life applications of conservation strategies.

Exercise Questions (Q.1 to Q.10):

  • Answers to conceptual questions on biodiversity loss and its consequences.

  • Explanation of in situ vs ex situ conservation methods.

  • Discussion on the value of biodiversity—ecological, economic, and ethical.

  • Graph-based questions on species-area relationships.

Download Chapter 15 Solutions PDF – Biodiversity and Conservation

Access a free, downloadable PDF with complete NCERT solutions and diagrams to aid revision and exam success.

What’s Included:

  • Well-structured, easy-to-read solutions.

  • Visual aids for better concept retention.

  • Quick reference glossary of important terms.

Recommended Preparation Tips:

  • Focus on HIPPO – the five major causes of biodiversity loss.

  • Memorize the difference between in situ and ex situ conservation with examples.

  • Study biodiversity hotspots in India and their significance.

  • Understand the species-area relationship and be able to interpret related graphs.

  • Be aware of international treaties like the CBD and the purpose of the IUCN Red List.

Additional Study Resources:

  • Chapter 15 Biology Notes – Biodiversity and Conservation.

  • NCERT Exemplar Problems and Solutions.

  • NEET-level MCQs and assertion-reason questions.

  • Flashcards for biodiversity terms and conservation types.

  • Quick-revision infographic on conservation strategies.

Understanding the Value of Biodiversity

Chapter 15 emphasizes the importance of preserving biodiversity not only for ecological balance but also for the well-being of current and future generations. By studying this chapter, students become more aware of their role as responsible citizens of the planet and the need to protect Earth’s rich biological heritage.

Master this chapter to contribute meaningfully toward a sustainable and biodiverse future.

NCERT Solutions for Class 12 Biology Chapter 15 – Biodiversity and Conservation

Question 1. Name the three important components of biodiversity.

Answer: The three components of biodiversity are:

  • Genetic diversity
  • Species diversity
  • Ecological diversity

Question 2. How do ecologists estimate the total number of species present in the world?

Answer: Ecologists estimate the total number of species by comparing species richness of well-studied groups between different regions (tropics, temperate, or polar). They commonly use species density (number of species per m²), species abundance, and proportional abundance indices to measure and estimate overall biodiversity.

Question 3. Give three hypotheses for explaining why tropics show greatest levels of species richness.

Answer:

  • Tropics have a more stable climate, allowing species to survive without major natural disturbances.
  • Warm temperature and high humidity promote year-round productivity and species survival.
  • Higher solar energy input in tropical areas increases primary productivity, supporting a wider range of species.

Question 4. What is the significance of the slope of regression in a species-area relationship?

Answer: The slope of regression (regression coefficient) indicates the rate at which species richness increases with area. For smaller areas, it remains relatively constant (0.1–0.2). Over large areas like continents, it ranges from 0.6 to 1.2. It helps in comparing biodiversity patterns across different scales.

Question 5. What are the major causes of species losses in a geographical region?

Answer: Major causes include:

  • Natural disturbances like forest fires, famines, and droughts
  • Habitat destruction and displacement due to human activities
  • Overexploitation of species
  • Pollution and intensive agricultural practices
  • Over-specialization of species leading to extinction under environmental changes

Question 6. How is biodiversity important for ecosystem functioning?

Answer: Biodiversity ensures:

  • Higher productivity
  • Efficient recycling of energy and matter
  • Stability and resilience against disturbances
  • Alternatives at each trophic level for continued functioning
Without biodiversity, ecosystems may collapse as food chains and natural cycles would be disrupted.

Question 7. What are sacred groves? What is their role in conservation?

Answer: Sacred groves are forest patches around places of worship protected by local communities. Cutting trees is strictly prohibited in these regions. They serve an important conservation role by protecting rare, endemic, and threatened plant and animal species.

Question 8. Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?

Answer: Plant roots bind the soil firmly, reducing erosion caused by wind and water. Plants also enhance soil porosity, allowing water to infiltrate rather than runoff, thus controlling floods and maintaining soil fertility.

Question 9. The species diversity of plants (22%) is much less than that of animals (72%). What could be the explanation for how animals achieved greater diversification?

Answer: Animals exhibit greater adaptability due to their nervous systems and mobility. Their ability to actively respond to environmental changes and migrate across habitats leads to faster diversification and evolution compared to stationary plants.

Question 10. Can you think of a situation where we deliberately want to make a species extinct? How would you justify it?

Answer: Humans deliberately aim to eradicate disease-causing organisms such as the poliovirus. Eradicating such harmful species is justified as it improves public health without disturbing ecological balance.