NCERT Solutions Class 12 Biology Chapter 13 Biodiversity and Conservation

In Class 12 Biology Chapter 13, Biodiversity and Conservation, students learn about the wide variety of life forms on Earth and why protecting them is important for the future of our planet. This chapter explains different levels of biodiversity, patterns of species distribution, and the major threats that lead to the loss of plants and animals. It also introduces conservation strategies such as protected areas, wildlife laws, and sustainable use of natural resources, helping students understand how humans can play a role in preserving nature.

ALLEN is offering expertly structured NCERT Solutions to assist students in grasping these global environmental issues. Our experts have tailored these solutions to help students provide the precise, point-wise answers that CBSE examiners look for, particularly in high-weightage questions. By studying with ALLEN’s professional resources, students can master the technical nuances of ecology while preparing effectively for both their board finals and medical entrance exams.

1.0Download NCERT Solutions Class 12 Biology Chapter 13 Biodiversity and Conservation : Free PDF

This chapter explains how living species are classified, why they are disappearing, and how they can be protected. The NCERT Solutions for Class 12 Biology Chapter 13 Biodiversity and Conservation help students revise key ideas and practise textbook questions easily. Download the free PDF now to study anytime and prepare confidently for exams.

2.0Key Concepts of Class 12 Biology Chapter 13 Biodiversity and Conservation

The chapter focuses on understanding biological variety and methods to protect it. Some of the key lessons covered in this chapter are given below:

• Levels of Biodiversity: Understanding genetic, species, and ecosystem diversity.
• Patterns of Biodiversity: Learning about latitudinal gradients and species–area relationships.
• Importance of Biodiversity: Studying ecological, economic, and ethical values of living organisms.
• Loss of Biodiversity: Understanding causes like habitat destruction, pollution, overexploitation, and invasive species.
• Conservation Strategies: Learning about in situ and ex situ conservation methods.
• Protected Areas: Studying national parks, wildlife sanctuaries, and biosphere reserves.
• International Efforts: Understanding global agreements and organisations for biodiversity protection.

3.0NCERT Class 12 Biology Chapter 13 Biodiversity and Conservation : Detailed Solutions

1. Name the three important components of biodiversity. 

Ans: The three important components of biodiversity are:

• Genetic Diversity – It refers to the diversity in genes within a species. It enables organisms to adapt to environmental changes.
• Species Diversity – It refers to the variety of species present in a particular region.
• Ecological Diversity – It refers to the diversity of ecosystems such as forests, deserts, wetlands, and grasslands.

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

Ans: Ecologists estimate the total number of species on Earth by using statistical methods based on the number of species identified in well-studied taxonomic groups. They analyse the ratio of known to unknown species in these groups and use it to estimate the total number of species worldwide.

Another method involves studying species richness patterns in specific regions and extrapolating the data to global levels.

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

Ans: The three hypotheses explaining greater species richness in tropical regions are:

• Evolutionary Time Hypothesis : Tropical regions have remained relatively undisturbed for long periods, allowing more time for species evolution and diversification.
• Climatic Stability Hypothesis : Tropical climates are stable and less seasonal, which supports the survival and specialization of species.
• Energy Availability Hypothesis : Tropical regions receive more solar energy and rainfall, resulting in higher productivity and supporting a larger number of species.

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

Ans: The slope of regression in a species–area relationship indicates the rate at which the number of species increases with an increase in the area. It is represented by the constant Z in the equation S = CAᶻ, where S is species richness and A is area.

The slope value is generally low for smaller areas. This indicates a gradual increase in species number with increasing area. However, for very large areas like continents, the slope is steeper, showing a greater increase in species diversity with area.

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

Ans: The major causes of species loss are:

• Habitat Loss and Fragmentation : Destruction of natural habitats due to urbanisation, agriculture, and deforestation leads to species extinction.
• Over-exploitation : Excessive hunting, fishing, and harvesting of species reduce their population drastically.
• Alien Species Invasion : Introduction of non-native species can harm native species by competition or predation.
• Co-extinctions : Extinction of one species leads to the loss of other species that depend on it.

6. How is biodiversity important for ecosystem functioning?

Ans: Biodiversity plays a crucial role in maintaining ecosystem functioning in the following ways:

• Enhances Productivity : Ecosystems with greater biodiversity show higher productivity and stability.
• Maintains Nutrient Cycling : Different species contribute to recycling nutrients and maintaining soil fertility.
• Provides Ecosystem Stability : Higher biodiversity increases resistance to environmental disturbances.
• Supports Ecosystem Services : Biodiversity helps in pollination, water purification, climate regulation, and food supply.

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

Ans: Sacred groves are patches of forest or natural vegetation that are protected by local communities due to religious or cultural beliefs. These areas are usually dedicated to local deities and are preserved without any human interference.

Role in conservation:

• They help in conserving rare, endangered, and endemic species.
• They protect biodiversity by preventing deforestation and habitat destruction.
• They maintain ecological balance and preserve traditional conservation practices.

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

Ans: Biotic components such as plants, trees, grasses, and microorganisms help control floods and soil erosion in the following ways:

• Plant roots bind the soil particles together and prevent soil erosion.
• Vegetation slows down the surface water flow. This allows water to percolate into the soil, which reduces flooding.
• Excess rainwater is absorbed by the forests and regulate water flow in rivers and streams.
• Microorganisms help in improving soil structure and fertility, which increases water retention capacity.

9. 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? 

Ans: Animals have achieved greater diversification due to the following reasons:

• Animals have greater adaptability to different environments because of their mobility.
• They show more complex body structures and behavioural patterns, allowing them to occupy diverse ecological niches.
• Animals have developed varied feeding habits and survival strategies, which promote diversification.
• Evolutionary changes and interactions such as competition and predation have contributed to the formation of new animal species.

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

Ans:

• Yes, there are certain situations where humans may deliberately try to eliminate a species, particularly when it is harmful to human health, agriculture, or the environment.
• For example, disease-causing organisms such as pathogens or harmful pests may be intentionally eradicated. The elimination of the smallpox virus is an example where deliberate efforts were made to remove a harmful organism to protect human life. Similarly, attempts are made to control mosquito species that spread diseases like malaria or dengue.
• This can be justified because such species pose serious threats to human health, food security, or ecological balance. However, such actions must be carried out carefully after scientific evaluation to ensure that the removal of the species does not disturb the ecosystem or lead to unintended consequences.

4.0Key Features and Benefits of Class 12 Biology Chapter 13 Biodiversity and Conservation

• Real-world examples help students relate textbook concepts to forests, oceans, and wildlife reserves.
• Comparison-based summaries make it easier to distinguish between conservation methods and biodiversity levels.
• Practice questions improve confidence in answering environment-focused and case-study problems.
• Visual learning through charts supports quick revision before board examinations.
• Strong conceptual base supports NEET preparation in ecology and conservation-related sections.
• Simple language helps students connect scientific ideas with everyday environmental issues.