Ecological Role & Economic Potential: NBSE Class 12 Environment

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Get summaries, questions, answers, solutions, notes, extras, PDF and guides for Chapter 3 Ecological Role and Economic Potential of Biodiversity: NBSE Class 12 Environment (Environmental Education) textbook, which is part of the syllabus of students studying under the Nagaland Board. These solutions, however, should only be treated as references and can be modified/changed.

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Summary
Textbook solutions
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- Questions and Answers
- MCQs

Summary

All the different kinds of life, like plants and animals, in an area is called biodiversity. It is very important for how nature works. Ecosystems are communities of living things and their environment. They include different jobs for species, how energy flows, and how food is shared. An area with many types of habitats and ecosystems has high biodiversity. Every species has a function.

Ecosystems support us by keeping soil healthy, helping plants make seeds through pollination, and cleaning air and water. They also help control climate and reduce disasters like floods. A place with more kinds of life is stronger and can handle stress better. India has special regions, like the Western Ghats, with many unique species found only there. An ecosystem with many different species can adapt to changes more easily. More types of life make an ecosystem stable.

Living things depend on each other. If one kind of animal or plant disappears, it creates problems. For example, fewer snakes might mean more rats eating crops. Organisms are linked through food chains. If a part of this chain breaks, it affects the variety of life. Sometimes, nature faces a crisis when many living things and their homes are at risk. It’s like how we found penicillin from a mold; if it had vanished before we knew its use, it would have been a loss.

Interactions between species can be helpful, like bees and flowers, which is called mutualism. Or one might benefit while the other is unaffected, like a small fish traveling with a shark; this is called commensalism. Sometimes, one harms another, such as in predation, where one animal hunts another, or when parasites live on other creatures.

India has an amazing variety of life, meaning it has so many different plants and animals that it is called a “megadiversity nation.” It has diverse lands, from rainforests to deserts. India is home to a large share of the world’s animals and plants, including many mammals, birds, reptiles, and thousands of plant types. Its geography and history helped create this richness. India also has great variety in its farm crops and animals.

Biodiversity is also economically important, meaning it helps us get or make things we need. It provides resources for food, medicine, and products like cosmetics. ‘Agro-biodiversity’ refers to the variety in farm plants. Biodiversity gives us food, as plants are the foundation of food chains. Wild plants provide medicines, like digitalis from the foxglove plant for heart issues or quinine from the cinchona tree for malaria. Industries use biodiversity for wood, cotton, and oils. Animals provide silk, wool, and help in farming. Nature-rich areas attract tourists, which brings economic benefits. The sea also offers many resources. Importantly, plants produce the oxygen we all need to breathe. Animals and tiny living things like microbes also play parts, such as breaking down waste or making soil healthy.

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Textbook solutions

Short Answer Questions

1. What is ecosystem diversity?

Answer: Ecosystem diversity is understood to be defined as the variety of different ecosystems that exist within a specific geographical area. It is further detailed that this encompasses the different habitats, the communities of organisms, and also the ecological processes that are occurring within these ecosystems. As an illustration, it is mentioned that a landscape which includes forests, wetlands, grasslands, and rivers is an example of exhibiting high ecosystem diversity. It is also stated that each of these ecosystems provides unique contributions to the overall health and functioning of the environment. Furthermore, the maintenance of ecosystem diversity is described as being vital for supporting a wide array of species and for providing essential ecosystem services to humans.

2. What do you understand by stable ecosystem?

Answer: I understand that a stable ecosystem is one that exhibits several key characteristics. Firstly, it should not show too much variation in productivity from year to year. Secondly, it must be either resistant or resilient to occasional disturbances, whether they are natural or man-made. And thirdly, it must also be resistant to invasions by alien species. A stable community, therefore, is one that maintains its structure and function over long periods despite environmental changes or disturbances.

3. Give the role of biodiversity in discovering penicillin.

Answer: The role of biodiversity was crucial in the discovery of penicillin. Penicillin is an antibiotic that was accidentally discovered by Alexander Fleming when he observed that the mold Penicillium notatum, a naturally occurring microorganism, inhibited the growth of Staphylococcus bacteria. This specific mold, with its unique antibiotic-producing properties, was a component of the existing biodiversity. Without the natural occurrence and diversity of microorganisms, including various molds like Penicillium, this life-saving drug would not have been found. The discovery highlights how organisms within the vast spectrum of biodiversity can possess unique biochemical properties beneficial to humans.

4. What do you know about megadiversity nation?

Answer: A megadiversity nation is one of a group of countries that harbor the majority of the Earth’s species and a high number of endemic species. These nations are characterized by exceptionally rich biodiversity, meaning they have a vast variety of life forms, including plants, animals, fungi, and microorganisms, within their borders. The concept is used to prioritize conservation efforts, as protecting biodiversity in these countries can have a significant impact on global species preservation. India is recognized as one of the 17 megadiversity countries in the world, possessing a significant proportion of the world’s biodiversity.

5. What do you understand by the term ‘niche’?

Answer: What I understand by the term ‘niche’ is that it describes the unique functional role and position of a species within its habitat or ecosystem. This encompasses how it obtains its food, the specific habitat it occupies, its interactions with other species, and its overall impact on the environment.

6. How many varieties of rice, pulses have been recorded by gene banks in India?

Answer: It has been recorded by gene banks in India that there are over 50,000 genetically different strains of rice. Additionally, these gene banks have documented and conserved a substantial number of pulse varieties, with records indicating more than 34,000 accessions of various pulses.

7. What is ecological hierarchy? (Short Answer Questions)

Answer: Ecological hierarchy is understood as the arrangement of biological organisms and their interactions in a series of levels, ordered from simpler, smaller units to more complex, larger systems. This hierarchy typically includes the organism, which is an individual living being; the population, a group of individuals of the same species in a particular area; the community, which comprises all populations of different species interacting in a specific area; the ecosystem, which includes the community and its non-living physical environment; the biome, a large geographical area characterized by specific climate conditions and dominant plant and animal life; and finally, the biosphere, which encompasses all ecosystems on Earth.

8. Define the following

(a) Mutualism

Answer: Mutualism is described as an interaction in which both the interacting species are benefited.

(b) Commensalism

Answer: Commensalism is an interaction where one species is benefited and the other is neither benefited nor harmed.

(c) Symbiosis

Answer: Symbiosis is understood as a close and prolonged association between organisms of different species. This term encompasses various types of interactions, such as mutualism and commensalism, where organisms live together.

Long Answer Questions

1. Describe the ecological role of biodiversity.

Answer: Biodiversity plays a crucial ecological role by contributing to many aspects of ecosystem structure and function. It is understood that species, with their unique genetic make-up, perform various functions within an ecosystem. For instance, some species capture energy, some produce organic material, some contribute to the decomposition of organic matter, and others are involved in nutrient cycling. The more diverse an ecosystem is, the more stable it tends to be, meaning it can better withstand and recover from various disturbances. This stability is often referred to as ecosystem resilience. Biodiversity also underpins essential ecosystem services, such as pollination, which is vital for plant reproduction and food production; soil formation and maintenance, which supports plant life; water purification, where diverse microbial and plant communities filter and clean water; nutrient cycling, involving the movement and reuse of essential elements like carbon, nitrogen, and phosphorus; and climate regulation, where forests and oceans, rich in biodiversity, act as carbon sinks. Furthermore, a rich variety of species ensures that if one species is affected by a change, others may be able to perform similar functions, thereby maintaining the overall health and processes of the ecosystem.

2. What do you understand by ecological crisis?

Answer: From my understanding, an ecological crisis refers to a situation where the environment of a species or a population undergoes critical changes that destabilize its continued existence. It signifies a point where the life-supporting capacity of an ecosystem is so severely degraded, either due to natural calamities or, more commonly in recent times, due to human activities, that it poses a substantial threat to the survival of organisms, including humans. This crisis can manifest as widespread loss of biodiversity, depletion of natural resources like fresh water and fertile soil, extensive pollution of air, water, and land, and disruptions to fundamental ecological processes such as climate patterns and nutrient cycles. Essentially, it is a state where the ecological balance is so disturbed that the environment’s ability to sustain life and provide essential services is critically compromised, leading to potentially irreversible damage and a significant decline in the quality of life or even survival for the affected populations.

3. How is an ecosystem with a high degree of genetic biodiversity able to adapt to environmental changes?

Answer: An ecosystem with a high degree of genetic biodiversity is significantly more capable of adapting to environmental changes due to the wide array of genetic variations present within its constituent populations. Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of a species, and it is the raw material for evolution. When environmental conditions change, for example, due to climate shifts, the introduction of new diseases, or pollution, these changes impose new selective pressures on the organisms living in that ecosystem.

In a population with high genetic diversity, there is a greater likelihood that some individuals will possess genetic traits, or alleles, that make them better suited to the new conditions. These advantageous traits might include resistance to a new pathogen, tolerance to higher temperatures, an ability to utilize a different food source, or greater efficiency in water use during a drought. Individuals possessing these beneficial traits are more likely to survive, reproduce, and pass these advantageous genes on to their offspring. Over generations, the frequency of these adaptive traits increases within the population, leading to the adaptation of the species to the new environmental conditions.

Conversely, if a population has low genetic diversity, it means that most individuals are genetically similar. If this limited genetic makeup does not include traits that confer an advantage under the new environmental conditions, the population may struggle to survive. It might experience a significant decline in numbers or even face local extinction because few, if any, individuals are equipped to cope with the change.

Therefore, a high degree of genetic biodiversity within an ecosystem ensures that there is a larger pool of potential adaptations available. This genetic reservoir increases the probability that at least some species, and some individuals within those species, will be able to withstand and adapt to environmental disturbances. This, in turn, contributes to the overall resilience and persistence of the ecosystem as a whole, allowing it to continue functioning and providing services even as conditions change. The presence of diverse genetic blueprints means that the ecosystem is not “putting all its eggs in one basket” genetically, thereby enhancing its capacity for evolutionary response and long-term survival in a dynamic world.

4. How have geological events in landmass of India provided conditions for a high level of diversity? Explain.

Answer: The unique geological history of the Indian landmass has played a crucial role in creating conditions conducive to a high level of biodiversity. India’s journey as a drifting landmass, originating from Gondwanaland, and its eventual collision with the Asian mainland, led to the formation of the mighty Himalayas. This monumental geological event not only created a formidable physical barrier but also resulted in diverse altitudinal zones, ranging from alpine to tropical, each supporting unique flora and fauna. The uplift of the Himalayas also profoundly influenced India’s climate, particularly the monsoon patterns, which are vital for the subcontinent’s varied ecosystems.

Furthermore, the ancient peninsular plateau, with its varied rock formations and geological stability, has allowed for the long-term evolution and persistence of many species. Volcanic events, such as the Deccan Traps formation, also contributed to specific soil types and topographical features that support distinct biological communities. The development of the vast Indo-Gangetic plains, formed by alluvial deposits from the Himalayan rivers, created fertile lands that became cradles for rich agricultural biodiversity and associated ecosystems. These diverse geological foundations have resulted in a mosaic of habitats, including different forest types, grasslands, wetlands, coastal, and marine ecosystems, each providing niches for a wide array of species, thus fostering high species richness and endemism across the Indian subcontinent. The varied soil types derived from different geological substrates further contribute to plant diversity, which in turn supports a diverse faunal population.

5. Justify the statement: “For every product, biodiversity is the first resource of daily life.”

Answer: The statement that for every product, biodiversity is the first resource of daily life can be justified by examining the origins of the vast majority of goods and services essential for human existence. Our fundamental needs, such as food, clothing, and shelter, are directly met by biodiversity. All food items, whether plant-based like cereals, fruits, and vegetables, or animal-based like meat, fish, and dairy products, originate from the diversity of life forms. Similarly, materials for clothing, such as cotton, silk, wool, and linen, are derived from plants and animals.

Beyond these basic necessities, many other products integral to daily life also have their roots in biodiversity. Wood, a primary material for shelter, furniture, and fuel, comes from trees. A significant number of medicines, both traditional and modern, are extracted from plants, animals, and microorganisms. Even many industrial products, including paper, rubber, resins, gums, and natural dyes, are sourced from biological resources. Furthermore, ecosystem services provided by biodiversity, such as pollination essential for crop production, clean air and water purification by forests and wetlands, and soil fertility maintained by microorganisms, underpin the production of almost all other resources. Therefore, from the most basic to more complex items, biodiversity serves as the foundational resource upon which human societies and economies are built, making it indeed the first resource for nearly every product in daily life.

6. Give the details of important economic commodities that biodiversity supplies to mankind.

Answer: Biodiversity supplies a vast array of important economic commodities to mankind, forming the bedrock of many industries and livelihoods. These can be broadly categorized as follows:

First, food resources are paramount. This includes all cultivated crops such as cereals like rice, wheat, and maize; pulses like lentils and beans; a wide variety of fruits and vegetables; oilseeds providing edible oils; and spices and condiments that add flavor and value to food. Animal-based food commodities include meat from livestock and poultry, fish and other seafood from marine and freshwater ecosystems, and dairy products. Beverages like tea, coffee, and cocoa are also significant economic commodities derived from plant biodiversity.

Second, timber and other wood products are crucial. Forests provide timber for construction, furniture making, and other structural uses. Wood is also processed into pulp for paper and paper products, and fuelwood remains a primary energy source for a large portion of the global population. Non-timber forest products (NTFPs) like bamboo, rattan, and various medicinal plants also hold substantial economic value.

Third, fibers for textiles and other industrial uses are supplied by biodiversity. Cotton is a leading natural fiber for clothing. Silk, obtained from silkworms, is a valuable textile. Wool from sheep and other animals, jute for sacking and ropes, and coir from coconuts are other economically important fibers.

Fourth, medicinal resources from biodiversity are extensive. A large number of plant species are used in traditional medicine systems worldwide, and many modern pharmaceuticals have been derived from, or inspired by, compounds found in plants, animals, and microorganisms. Quinine from cinchona bark and aspirin originally from willow bark are classic examples.

Fifth, industrial products derived from biodiversity include natural rubber from the rubber tree, gums and resins used in adhesives, food products, and incense; tannins for leather processing; natural dyes for textiles and food; and essential oils used in perfumery, cosmetics, and aromatherapy. Waxes, such as beeswax, also have various industrial applications.

Sixth, ornamental and recreational commodities also contribute to the economy. This includes horticultural products like ornamental plants and cut flowers, aquarium fish, and wildlife that supports ecotourism industries.

Finally, genetic resources from biodiversity are invaluable for agriculture and biotechnology. Wild relatives of crop plants provide genes for disease resistance, improved yield, and stress tolerance, which are crucial for food security and agricultural development.

Think and Answer

1. Do you think man’s activities in the name of progress today are detrimental to biodiversity conservation? Discuss.

Answer: Yes, I do think that many of man’s activities undertaken in the name of progress today are significantly detrimental to biodiversity conservation. While progress aims to improve human living standards, it often comes at a considerable cost to the natural world. For instance, large-scale industrialization and urbanization lead to extensive habitat destruction and fragmentation, which are primary drivers of biodiversity loss. Forests are cleared for agriculture, infrastructure projects like dams and highways, and urban expansion, directly eliminating the homes of countless species and disrupting ecological processes. Furthermore, the pollution generated by industries and modern agricultural practices, such as the use of pesticides and chemical fertilizers, contaminates soil and water bodies, harming or killing non-target organisms and disrupting food chains. The pursuit of resources to fuel progress, like mining and logging, often involves unsustainable extraction methods that degrade ecosystems and reduce species populations. Even advancements in transportation have inadvertently facilitated the spread of invasive alien species, which can outcompete native flora and fauna, leading to their decline. Climate change, largely driven by the burning of fossil fuels for energy – a cornerstone of modern progress – is altering habitats, changing species distributions, and increasing the frequency of extreme weather events, all of which negatively impact biodiversity. While some aspects of progress, such as technological advancements, can be harnessed for conservation efforts, the overwhelming trend currently indicates that the scale and nature of human activities geared towards conventional notions of progress often prioritize short-term economic gains over long-term ecological sustainability, thereby posing a severe threat to the conservation of our planet’s rich biodiversity.

2. How have geological events in landmasses of India provided conditions for high level of biological diversity?

Answer: Geological events in the landmasses of India have played a crucial role in creating diverse physical conditions and varied climatic zones, which in turn have provided the necessary conditions for a high level of biological diversity.

Firstly, the northward drift of the Indian Plate from Gondwanaland and its subsequent collision with the Eurasian Plate, commencing around 50 million years ago, led to the monumental uplift of the Himalayas. This orogenic event created a vast range of altitudinal gradients, from tropical foothills to alpine peaks, resulting in a multitude of distinct habitats and microclimates that support a wide array of specialized flora and fauna. The Himalayas also act as a climatic barrier, influencing monsoon patterns and creating diverse precipitation regimes across the subcontinent.

Secondly, the Deccan Traps, formed by massive volcanic eruptions around 66 million years ago, covered a large part of peninsular India with basaltic lava. The weathering of these rocks has given rise to fertile black soils, supporting specific types of vegetation and associated faunal communities. The varied topography resulting from this volcanic activity also contributes to habitat diversity.

Thirdly, the Indian peninsula itself is an ancient landmass, part of the Gondwana supercontinent, which allowed for long periods of evolutionary isolation for certain lineages before the collision with Asia. This has contributed to the presence of endemic species.

Furthermore, the formation of the Indo-Gangetic plains, a vast alluvial expanse created by sediment deposition from the Himalayan rivers, has provided extensive fertile lands supporting rich riparian ecosystems and a different set of species adapted to these lowland conditions.
The long coastline of peninsular India, with its diverse features such as estuaries, lagoons, mangroves, and coral reefs, is also a product of geological and geomorphological processes, providing unique marine and coastal habitats that harbor significant biodiversity.

The presence of distinct geological formations, varied soil types derived from different parent rocks, and the complex tectonic history have collectively resulted in a mosaic of landscapes, from arid deserts in the west to lush rainforests in the Western Ghats and Northeast, each with its unique assemblage of species, making India a megadiverse country.

3. How is biodiversity the most important wealth of the planet?

Answer: Biodiversity is arguably the most important wealth of the planet because it underpins the very functioning of ecosystems and provides a vast array of essential goods and services upon which all life, including human civilization, depends.

Firstly, biodiversity is fundamental to the provision of crucial ecosystem services. These include the production of oxygen and sequestration of carbon dioxide by plants, which regulate the global climate. Pollination of crops by insects, birds, and bats is essential for food production. Wetlands and forests purify water and mitigate floods. Microorganisms in the soil decompose organic matter, recycle nutrients, and maintain soil fertility, which is vital for agriculture. Healthy, diverse ecosystems also offer natural pest and disease control. Without these services, which are direct outcomes of biological diversity, the planet’s life-support systems would collapse.

Secondly, biodiversity is a direct source of economic wealth. It provides us with food (crops, livestock, fisheries), medicines (many derived from plants and microorganisms), timber, fiber, fuel, and other raw materials for industries. Genetic diversity within species is a critical resource for improving crop yields, disease resistance, and adapting agriculture to changing environmental conditions. Ecotourism and recreation based on rich biodiversity also generate significant income for many communities and nations.

Thirdly, biodiversity contributes to human health and well-being in numerous ways beyond direct resource provision. Exposure to nature and green spaces has been linked to improved mental and physical health. Biodiversity also holds immense cultural, aesthetic, spiritual, and educational value for societies across the globe.

Fourthly, biodiversity enhances the resilience of ecosystems. Ecosystems with high species diversity are generally more stable and better able to withstand and recover from disturbances such as climate change, pollution, or natural disasters. This resilience is crucial for ensuring the long-term sustainability of ecosystem services.

Finally, there is an intrinsic and ethical dimension to biodiversity’s importance. Many believe that all species have a right to exist, irrespective of their direct utility to humans, and that we have a moral obligation to act as stewards of the planet’s biological heritage for future generations.
Therefore, because biodiversity forms the foundation of ecological stability, provides essential life-support services, fuels economies, supports human health, and holds profound ethical and cultural significance, it can be considered the most fundamental and indispensable wealth of our planet, upon which all other forms of wealth ultimately depend.