NCERT Solutions for Class 12 Biology Chapter 13 Biodiversity and Conservation

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The exercise questions of the Biodiversity and Conservation chapter are given below. Practicing the Class 12 Biology Chapter 13 Biodiversity and Conservation question answer, designed according to the NCERT curriculum, allows students to score well in exams without any confusion.

Q1. Name the three important components of biodiversity.

Answer:

Biodiversity refers to the vast variety present among the various life forms. The three components of biodiversity are

1. Genetic diversity

2. Species diversity

3. Ecosystem diversity

Q2. How do ecologists estimate the total number of species present in the world?

Answer:

To estimate the number of species present on Earth, ecologists statistically compare the species richness of well-studied groups of insects of tropical and temperate regions, and these ratios are extrapolated to other groups of plants and animals to estimate the species richness found on Earth. As per estimates, about 7 million species are present on Earth.

Q3. Give three hypotheses for explaining why tropics show the greatest levels of species richness.

Answer:

Tropics show the greatest level of species richness due to the following reasons (hypotheses)

1. The climate of tropical areas is more stable than that of temperate areas. So the local populations continuously live in the absence of natural disturbances.

2. Tropical communities are highly productive and can support a wide range of other species. This is mainly because the tropics receive more solar energy.

3. In the tropics, there are warm temperatures and high humidity. Such conditions are favorable for varieties of fungi, plants, and algae.

Q4. What is the significance of the slope of regression in a species-area relationship?

Answer:

The slope of the regression has a major role in determining the species-area relationship. In smaller areas, the slope of regression is similar regardless of the taxonomic group or region. On the other hand, in the case of larger areas, the curve is steeper. Biodiversity also increases from higher to lower altitudes.

Q5. What are the major causes of species losses in a geographical region?

Answer:

The major causes of species losses in a geographical region are as follows;

1. Habitat loss and fragmentation

2. Over-exploitation

3. Alien species invasion

4. Co-extinction

Q6. How is biodiversity important for ecosystem functioning?

Answer:

Importance of biodiversity in ecosystem functioning

1. Biodiversity is important for maintaining stability, productivity, resilience, alternative pathways, and overall health of a particular ecosystem.

2. A scientist named David Tilman confirmed that the higher the biodiversity higher the productivity of the ecosystem, as more plants are there to photosynthesize and more decomposers are there to recycle the waste of the ecosystem. He also proved that if the biodiversity of an area is high, then a year-to-year variation in total biomass will be less, contributing to the overall stability of an ecosystem.

3. Rich biodiversity provides resilience against natural as well as man-made disturbances.

4. To clarify the importance of rich biodiversity on ecosystem functioning, the Rivet Popper hypothesis was proposed by Paul Ehrlich. He cited that the way in an airplane all parts are joined by thousands of rivets, in an ecosystem, all components are joined by species. As more and more rivets are removed, the parts of the airplane disassemble. Similarly, as species are removed, the functioning of the ecosystem also gets affected.

Q7. What are sacred groves? What is their role in conservation?

Answer:

Sacred groves are the traditionally protected patches of forests around places of worship where local tribal communities actively participate to protect these regions and do not allow to cutting of even a single branch of the tree because of religious reasons. Sacred groves in India are found in the Western Ghats of Karnataka, Maharashtra, Khasi and Jaintia hills in Meghalaya, Aravali hills in Rajasthan, and Sarguja, Chanda, and Bastar areas of Madhya Pradesh.

Role of sacred groves in the conservation of biodiversity

1. Sacred groves help in the protection of several rare, endangered, and endemic species.

2. In these regions, deforestation is strictly prohibited, and thus, they are biodiversity-rich areas.

Q8. Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?

Answer:

Ecosystem services refer to goods or benefits that we get from the ecosystem. Prevention of soil erosion and floods comes under the benefits provided by the ecosystem to us. The ecosystem includes both abiotic and biotic components. The biotic components are the living organisms present in an ecosystem. Biotic components play a role in providing ecosystem services. Some of these roles are as follows:

1. The roots of plants hold the soil particles very tightly. This prevents the erosion or degradation of the top layer of soil

2. Plants increase soil fertility and biodiversity.

3. The presence of plants also helps in controlling the flow of floods and leads to minimal destruction.

4. The roots of plants make the soil porous, thus allowing water to seep into the soil.

5. The carbon dioxide and oxygen balance are maintained in the ecosystem via plants and animals.

Q9. The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations for how animals achieved greater diversification?

Answer:

Animals have achieved greater diversification than plants due to the following reasons:

1. Animals possess a nervous system that allows them to sense stimuli and respond quickly, giving them survival advantages.

2. Animals are motile, which helps them escape competition, migrate to favorable habitats, and exploit diverse resources.

3. Being mobile and adaptable, animals are less affected by seasonal variations compared to plants.

4. Plants are stationary and need more evolutionary adaptations to obtain water, minerals, sunlight, and protection from herbivory.

Thus, animals evolved more diverse forms and functions compared to plants.

Q10. Can you think of a situation where we deliberately want to make a species extinct? How would you justify it?

Answer:

Yes, some harmful pathogens, i.e., disease-causing organisms with little or no role in the ecosystem, can be made to go extinct. Their extinction will not lead to any effect on the ecological balance. These pathogens may include smallpox virus, etc. Poliovirus is about to be eradicated. There are efforts to make this world free from diseases such as TB, AIDS, Malaria, etc. Since the microorganisms causing these diseases have no role to play in the environment, they can be made to get eradicated.

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Approach to Solve Biodiversity and Conservation Class 12 Question Answer

To solve the textbook questions effectively, one needs to understand the concepts first. The chapter has important terms, such as species richness, ecosystem diversity, and conservation strategies. All definitions are well-explained in the Class 12 Biology Chapter 13 Biodiversity and Conservation question answer. Making notes of the chapter is important, highlighting all the important points. The Class 12 Biology Biodiversity and Conservation question answer has all the solved exercise questions. Finally, one should refer to the NCERT Class 12 Solutions to have an overall idea of the chapter and build confidence before the exams.

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Important Questions of NCERT Class 12 Biology Chapter 13 Biodiversity and Conservation

This chapter helps students understand the variety of life forms on Earth and how we can protect them for future generations. To gain more clarity related to biodiversity, students can refer to the NCERT Solutions for Class 12 Biology Chapter 13 Biodiversity and Conservation.

Question 1: Which of the following groups exhibits more species diversity?

Options:

1. Gymnosperms

2. Algae

3. Bryophytes

4. Fungi

Answer: The correct answer is Option (4) Fungi.

Explanation:

Fungi and angiosperms harbor the highest species diversity. The estimated number of fungi species is 1.5 million, and only 120,000 have been described. They occupy the most critical ecological niches in decomposition, symbiosis, and as pathogens. Their ecological significance and biodiversity have made them one of the main groups of study interest in both biology and environmental science.

Question 2: Which of the following regions exhibits less seasonal variation?

Options:

1. Tropics

2. Temperates

3. Alpines

4. Both (a) & (b)

Answer: The correct answer is Option (1) Tropics

Explanation:

The tropics, situated between the Tropic of Cancer and the Tropic of Capricorn at approximately 23.5°N to 23.5°S, receive a consistent solar energy input annually due to the sun's near-vertical position over the area throughout the year.

Question 3: The historic convention on Biological Diversity held in Rio de Janeiro in 1992 is known as:

Options:

1. CITES Convention

2. The Earth Summit

3. G-16 Summit

4. MAB Program

Answer: The correct answer is Option (2), The Earth Summit

Explanation:

The historic Convention on Biological Diversity (CBD) occurred during the 1992 Earth Summit, officially the United Nations Conference on Environment and Development (UNCED), in Rio de Janeiro. The CBD's primary goals are threefold: conserving biodiversity, sustainably utilizing its components, and equitably sharing the benefits derived from genetic resources.

Question 4: Which of the following forests is known as the ‘lungs of the planet Earth’?

Options:

1. Taiga forest

2. Tundra forest

3. Amazon rainforest

4. Rainforests of North East India

Answer: The correct answer is Option (3) Amazon rainforest.

Explanation:

The Amazon rainforest is commonly known as the "lungs of the planet" because it has tremendous vegetation in its very large area, which absorbs carbon dioxide and produces oxygen through photosynthesis. With a size of around 5.5 million square kilometers, it is very responsible for regulating climate and biodiversity on Earth.

Question 5: The one-horned rhinoceros is specific to which of the following sanctuaries

Options:

1. Bitar Kanika

2. Bandipur

3. Kaziranga

4. Corbett Park

Answer: The correct answer is Option (3) Kaziranga

Explanation:

The correct answer is (3) Kaziranga. Kaziranga National Park is known to house almost two-thirds of the one-horned rhinoceros of the world and therefore is called a sanctuary for that species, an endangered species in the world. This national park in Assam, India, is recognized by UNESCO as a World Heritage Site, and it contains diversified ecosystems comprising grasslands and wetlands.

NCERT Exemplar Class 12 Solutions

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What Students Learn from Biodiversity and Conservation NCERT Solutions

Students go through this chapter to understand how life forms are distributed and why their protection is essential.

1. Learners understand the types of biodiversity, such as genetic, species, and ecosystem diversity.

2. They study the patterns of biodiversity, including latitudinal gradients and species–area relationships.

3. Students explore the causes of biodiversity loss, such as habitat destruction, over-exploitation, and the introduction of alien species.

4. With the help of the Biodiversity and Conservation Class 12 question answer, they learn the methods of in-situ and ex-situ conservation, such as national parks, biosphere reserves, and gene banks.

5. By practicing the Class 12 Biology Biodiversity and Conservation question answer, learners analyze the importance of conservation strategies and their applications in India and worldwide.

Why Class 12 Biology Chapter 13 Biodiversity and Conservation NCERT Solutions are Important?

The Biodiversity and Conservation chapter focuses on the variety of life that is present on the Earth and the need to protect it. The solutions for this chapter help students understand how biodiversity is classified and conserved.

• Class 12 Biology Chapter 13 Biodiversity and Conservation NCERT Solutions are important as they explain the types and levels of biodiversity, such as the genetic, species, and ecosystem diversity.
• Topics like patterns of biodiversity, species richness, and endemic species are included in the solutions in an easy-to-understand manner.
• Threats to biodiversity, such as habitat loss, overexploitation, and pollution, are covered, which are very important for competitive exams like NEET and board exams.
• Students will also strengthen their knowledge about methods of conservation, including in-situ and ex-situ strategies.

What Extra Should Students Study Beyond the NCERT for NEET?

Studying concepts beyond the NCERT will help in attaining conceptual clarity. By using the NCERT Solutions for Class 12 Biology Chapter 13 Biodiversity and Conservation, students can answer application-based questions easily. Some extra concepts that can be studied are given below.

NCERT Chapter-wise Solutions for Class 12 Biology

The chapter-wise solutions for all chapters are given below: