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Dimensions of Environment: NBSE Class 11 Environment
Get notes, summary, questions and answers, MCQs, extras, and PDFs of Chapter 1 “Dimensions of Environment” which is part of NBSE Class 11 Environment Education. However, the notes should only be treated as references and changes should be made according to the needs of the students.
If you notice any errors in the notes, please mention them in the comments
Summary
The chapter “Dimensions of Environment” explores the different aspects of the environment, highlighting its complexity and the interaction between its components. The environment is defined as the total conditions that surround us at any given time and place. It includes three key dimensions: physical, biological, and social or cultural.
The physical dimension consists of the lithospheric (solid), hydrospheric (liquid), and atmospheric (gaseous) environments. The lithosphere includes landforms and soil, which support life. The hydrosphere covers water bodies like oceans, rivers, and lakes, and is crucial for sustaining life. The atmosphere is a mixture of gases, mainly nitrogen and oxygen, that protects the earth from harmful solar radiation and regulates climate.
The biological dimension, also known as the biotic environment, includes all living organisms, categorized into producers, consumers, and decomposers. Producers, like plants, create food through photosynthesis. Consumers depend on plants or other animals for food, while decomposers break down dead organic matter, recycling nutrients back into the environment.
The social or cultural dimension reflects the human influence on the environment. Humans create social institutions, laws, and economic systems that interact with the physical and biological environments. The exploitation of natural resources, when not in harmony with the environment, leads to ecological imbalances and environmental problems.
The chapter also discusses the impact of human activities on the environment, such as deforestation, pollution, and wildlife extinction. It emphasizes the need for a sustainable approach to resource use to prevent further environmental degradation and ensure the survival of all life forms. The chapter concludes by stressing the importance of a balanced relationship between humans and the environment.
Textbook solutions
Multiple-Choice Questions
1. Which of the following is an inseparable part of the environment?
(a) Air and land
(b) Plant and water
(c) Man
Answer: c. Man
2. What is the main economic activity, in which people of Nagaland are involved?
(a) Weaving
(b) Agriculture
(c) Handicrafts
(d) Rearing of livestock
Answer: b. Agriculture
3. Which of the following does not qualify as the inseparable and vital part of the triad of constituents forming the environment?
(a) Physical dimension
(b) Biological dimension
(c) Economical dimension
(d) Social dimension
Answer: c. Economical dimension
4. Identify the second-level consumer among the following.
(a) Frog
(b) Earthworm
(c) Grasshopper
(d) Snake
Answer: a. Frog
5. What is the cause of extinction of many wildlife species in Nagaland?
(a) Poaching
(b) Illegal worldwide wildlife trading
(c) Habitat loss
(d) All the above
Answer: d. All the above
Short Answer Questions
1. Define the term environment.
Answer: Environment refers to the sum total of conditions which surround man at a given point in space and time.
2. What are the main dimensions of environment?
Answer: (a) Physical dimension
(b) Biological dimension
(c) Cultural or Social dimension
3. What do physical dimensions of environment include?
Answer: This dimension includes abiotic components such as space, landforms, water bodies, climate, soils, rocks and minerals. These elements help to determine the variable character of the human habitat, its opportunities as well as limitations.
4. Which aspects of non-living environment affect life?
Answer: The physical dimension of environment, which includes abiotic components such as space, landforms, water bodies, climate, soils, rocks, and minerals, affects life.
5. What is faunal environment?
Answer: It is the environment of the fauna. Fauna means all the animal life normally present in a given habitat at a given time.
6. Why is biosphere a self-sufficient biological system?
Answer: Earth’s living organisms interacting with their physical or abiotic environment (including air, land and water) form a giant and vast ecosystem called ecosphere or biosphere which is the largest and almost self-sufficient biological system.
Long Answer Questions
1. Which are the three main types of organisms in the biotic or biological environment?
Answer: The organisms in the biotic or biological environment are mainly of three types:
(i) Producers: These are mainly green plants and photosynthetic bacteria. They aid in fixing radiant energy of the sun and with the help of minerals gained from mud and water. They also manufacture complex organic substances such as carbohydrates, proteins, and lipids.
(ii) Consumers: These are heterotrophs that depend for their nutrition on the organic food manufactured by producers, the green plants. All types of animals, including humans, are consumers because they depend on plants (producers) for their food.
(iii) Decomposers: These are also called microconsumers. This term is used as they absorb only a fraction of decomposed organic matter. They bring about the decomposition of dead organic matter of both plants and animals. They help in returning mineral elements again to the medium of the pond and in running biogeochemical cycles.
2. What is meant by the floral environment?
Answer: Floral environment is the environment of the flora. Flora means all the plant life normally present in a given habitat at a given time. Though Nagaland is a small state, it has been endowed with a wide variety of forest types on account of its unique geographic location and wide range of physiographic terrain obtaining in the state. It has a rich and varied heritage of biodiversity owing to its varying vegetation. It varies from tropical rainforest to alpine vegetation and from evergreen forest to sub-tropical climatic region. Floral environment has taken the brunt of human development in many ways. Increasing number of human beings are encroaching on remaining wild lands even in those areas once considered relatively safe from exploitation, degradation and pollution.
It was estimated at one point in the 1980s that such forestlands were being cleared or converted at the rate of nearly 50 acres a minute; another estimate put the rate of 200,000 sq. km a year. In 1993, satellite data provided a rate of 5,800 sq. miles a year in the Amazon Basin area alone. This tropical deforestation has already resulted in the extinction of as many as 750,000 species, and is likely to eliminate millions if allowed to continue unchecked. This would mean the loss of a multiplicity of products food, fibres, medical drugs, dyes, gums and resins.
3. What do you understand by abiotic environment? Discuss.
Answer: Abiotic environment is a part of the physical dimension of the environment consisting of non-living elements. The abiotic components include elements such as space, landforms, water bodies, climate, soils, rocks, and minerals. These elements help to determine the variable character of the human habitat, its opportunities as well as limitations.
The physical dimension of the environment can further be divided into three broad categories: (i) Lithospheric (solid) environment, (ii) Hydrospheric (liquid) environment, (iii) Atmospheric (gaseous) environment.
Lithospheric environment covers about 30% of the earth’s surface and supports terrestrial life ranging from the arid deserts to the temperate forest and tropical rainforests. Hydrospheric environment consists of the earth’s water present in the oceans, rivers, lakes, soil, and as water vapours in the atmosphere. The atmospheric environment is a blanket of air surrounding the earth, consisting of a mixture of gases, mainly nitrogen (78%) and oxygen (21%).
4. Each physical, social and economic aspect of human beings has its unique importance, characteristics and functions in the biotic environment. Enumerate.
Answer: The physical man who is a part of the organismic inhabitants (biological community) needs basic elements of the physical environment, viz., space (habitat), food, air, water and he also releases wastes into the ecosystem like other members of the biological population. Second comes the social man who tends to create social institutions, establishes social organisations, makes laws, policies and principles to protect his very own existence, interest and social welfare. Thirdly, there is the economic man who tends to derive and use the resources from the physical and biotic environments with his skills and technologies. He is the one who transports matter and energy from one component of the ecosystem to the other. This function does not cause change in the ecosystem as long as its exploitation is in coordination with the natural environment. But when exploitation increases the critical limit, the balance of the environment gets disturbed and various environmental or ecological problems occur. These problems prove detrimental to human beings as well as all other members of the environment.
Think and Answer
1. How has man contributed to the change in different dimensions of environment?
Answer: Man has contributed to the change in different dimensions of the environment through various activities. In the physical dimension, large-scale deforestation, industrial development, and urbanization have led to the degradation of land, pollution of water bodies, and alteration of atmospheric conditions. In the biological dimension, the expansion of agricultural lands, poaching, and illegal wildlife trade have resulted in the loss of flora and fauna, leading to the extinction of several species. In the social or cultural dimension, human activities have led to changes in the social and economic environments, causing environmental problems when exploitation exceeds the critical limits, disturbing the balance of the ecosystem.
2. Suggest a few ways to protect our flora and fauna.
Answer: A few ways to protect our flora and fauna are:
- Conserve habitats: Protecting natural habitats from destruction and degradation ensures that flora and fauna have the necessary environment to thrive.
- Reduce pollution: Minimizing air, water, and soil pollution helps in maintaining the health of ecosystems, allowing plant and animal species to flourish.
- Implement sustainable practices: Encourage sustainable farming, logging, and fishing practices that do not overexploit natural resources.
- Enforce laws and regulations: Strong legal frameworks that protect endangered species and regulate activities that harm the environment are crucial for the conservation of biodiversity.
- Promote awareness and education: Raising awareness about the importance of preserving flora and fauna can lead to more community-driven conservation efforts.
Extras MCQs
1. What percentage of Nagaland’s population lived in villages according to the 2011 census?
A. 51.03%
B. 61.03%
C. 71.03%
D. 81.03%
Answer: C. 71.03%
Q. What are the three broad categories of the physical dimension of the environment?
A. Lithospheric, Hydrospheric, Atmospheric
B. Lithospheric, Biospheric, Atmospheric
C. Hydrospheric, Atmospheric, Biotic
D. Lithospheric, Biospheric, Hydrospheric
Answer: A. Lithospheric, Hydrospheric, Atmospheric
Q. Which component of the environment consists of a thin layer of mantle made up of soil and rocks?
A. Hydrosphere
B. Lithosphere
C. Atmosphere
D. Biosphere
Answer: B. Lithosphere
Q. What percentage of the Earth’s surface is covered by the Lithosphere?
A. 20%
B. 25%
C. 30%
D. 35%
Answer: C. 30%
Q. What percentage of the Earth’s water is contained in the oceans?
A. 87.2%
B. 92.2%
C. 97.2%
D. 99.2%
Answer: C. 97.2%
Q. Which gas constitutes 78% of the Earth’s atmosphere?
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Hydrogen
Answer: B. Nitrogen
Q. What is the main economic activity in Nagaland’s villages?
A. Weaving
B. Handicrafts
C. Livestock rearing
D. Agriculture
Answer: D. Agriculture
Q. What harmful effects are caused by chlorofluorocarbons (CFCs)?
A. Greenhouse effect
B. Global warming
C. Ozone layer damage
D. Acid rain
Answer: C. Ozone layer damage
Q. Which environmental dimension includes elements like climate, soils, rocks, and minerals?
A. Biological
B. Cultural
C. Physical
D. Social
Answer: C. Physical
Q. Which environmental component is involved in the formation of tides, cyclones, and hurricanes?
A. Lithosphere
B. Atmosphere
C. Biosphere
D. Hydrosphere
Answer: D. Hydrosphere
Q. What is the primary role of the different layers of the atmosphere?
A. Preventing global warming
B. Protecting from harmful rays and meteoroids
C. Supporting agriculture
D. Regulating ocean currents
Answer: B. Protecting from harmful rays and meteoroids
Q. Which of the following is not a dimension of the environment?
A. Physical
B. Biological
C. Chemical
D. Social
Answer: C. Chemical
Q. What physical condition allows water to exist in all three states on Earth?
A. Pressure
B. Temperature
C. Humidity
D. Gravity
Answer: B. Temperature
Q. Which atmospheric layer is primarily responsible for blocking harmful UV radiation?
A. Troposphere
B. Stratosphere
C. Mesosphere
D. Ionosphere
Answer: B. Stratosphere
Q. Which component of the environment includes both landforms and water bodies?
A. Biological
B. Social
C. Physical
D. Cultural
Answer: C. Physical
Q. What are the three types of organisms in the biotic environment?
A. Producers, Consumers, Decomposers
B. Producers, Predators, Scavengers
C. Carnivores, Herbivores, Omnivores
D. Plants, Animals, Microorganisms
Answer: A. Producers, Consumers, Decomposers
Q. What is the term used for green plants and photosynthetic bacteria in an ecosystem?
A. Consumers
B. Decomposers
C. Producers
D. Scavengers
Answer: C. Producers
Q. What is the role of decomposers in an ecosystem?
A. They produce organic substances
B. They consume other organisms
C. They decompose dead organic matter
D. They create energy from sunlight
Answer: C. They decompose dead organic matter
Q. Which environment is composed of all plant life present in a given habitat?
A. Faunal environment
B. Flora environment
C. Biotic environment
D. Abiotic environment
Answer: B. Flora environment
Q. What is the primary consequence of tropical deforestation as mentioned in the text?
A. Expansion of croplands
B. Extinction of species
C. Increased timber production
D. Growth of urban areas
Answer: B. Extinction of species
Q. In which regions are tropical forests being destroyed at an alarming rate?
A. Southeast Asia and Amazon Basin
B. Arctic and Antarctic
C. Europe and North America
D. Sahara and Gobi Deserts
Answer: A. Southeast Asia and Amazon Basin
Q. What caused rabbits to overrun the countryside in Australia?
A. Introduction of predators
B. Lack of natural enemies
C. Overpopulation of humans
D. Climate change
Answer: B. Lack of natural enemies
Q. What happens when new diseases are introduced to an area?
A. They strengthen local ecosystems
B. They eliminate all native plants
C. They may cause the death of many native plants
D. They increase biodiversity
Answer: C. They may cause the death of many native plants
Q. What is threatening the wildlife in Nagaland?
A. Increased rainfall
B. Expansion of agricultural lands
C. Introduction of new animal species
D. Lack of poaching laws
Answer: B. Expansion of agricultural lands
Q. What is the largest and almost self-sufficient biological system on Earth?
A. Ecosystem
B. Biosphere
C. Biotic environment
D. Abiotic environment
Answer: B. Biosphere
Q. What is one of the components of the abiotic environment that protects the Earth from ultraviolet radiation?
A. Lithosphere
B. Hydrosphere
C. Atmosphere
D. Biosphere
Answer: C. Atmosphere
Q. Which component of the environment consists of Earth’s water in oceans, rivers, lakes, atmosphere, and soil?
A. Biosphere
B. Lithosphere
C. Hydrosphere
D. Atmosphere
Answer: C. Hydrosphere
Q. Which aspect of human existence involves creating social institutions and establishing laws for social welfare?
A. Physical
B. Social
C. Economic
D. Biological
Answer: B. Social
Q. The environment’s biological dimension is divided into which two main components?
A. Lithosphere and Hydrosphere
B. Flora and Fauna
C. Atmosphere and Biosphere
D. Social and Economic
Answer: B. Flora and Fauna
Q. What happens when the exploitation of resources exceeds the critical limit?
A. The ecosystem becomes more productive
B. The environment remains balanced
C. Various environmental problems occur
D. Human population decreases
Answer: C. Various environmental problems occur
Q. Which term refers to all the animal life normally present in a given habitat at a given time?
A. Flora
B. Fauna
C. Biosphere
D. Lithosphere
Answer: B. Fauna
Q. What is the name of the abiotic component that consists of a thin mantle of soil supporting terrestrial life?
A. Biosphere
B. Lithosphere
C. Hydrosphere
D. Atmosphere
Answer: B. Lithosphere
Q. Which environmental dimension is associated with human skills and technologies to use resources?
A. Physical
B. Social
C. Economic
D. Biological
Answer: C. Economic
Q. What is the region of the Earth’s surface, sea, and air inhabited by living organisms called?
A. Lithosphere
B. Atmosphere
C. Biosphere
D. Hydrosphere
Answer: C. Biosphere
35. What is required to prevent environmental degradation and save human habitats?
A. Continuous economic growth
B. Increased exploitation of resources
C. A more rational and sustainable use of the environment
D. Decreased concern for the environment
Answer: C. A more rational and sustainable use of the environment
Extra Questions and Answers
1. What is the environment generally equated with?
Answer: The environment is generally equated with nature, wherein the physical components of the planet Earth, such as land, air, and water, support and affect life in the biosphere.
Q. What do some people argue should be included in the concept of the environment?
Answer: Some people have argued for the inclusion of only ‘air-land-water-plant’ in the concept of the environment, thus excluding human society from the ambit of the environment.
Q. How is the natural environment in many places around the world affected?
Answer: The natural environment in many places around the world is modified by humans, indicating human influence on nature.
Q. What is the main economic activity in Nagaland?
Answer: The main economic activity in Nagaland is agriculture. Besides agriculture, people are also engaged in rearing livestock, weaving, and handicrafts.
Q. What is the population distribution in Nagaland according to the 2011 census?
Answer: According to the 2011 census, 71.03% of the population in Nagaland lives in villages.
Q. What do studies conclude about the environment?
Answer: Studies have concluded that the environment is made up of three inseparable and vital constituents which are constantly interacting with each other. These constituents are the physical dimension, biological dimension, and cultural or social dimension.
Q. What are the three dimensions of the environment according to the text?
Answer: The three dimensions of the environment are: (a) Physical dimension (b) Biological dimension (c) Cultural or Social dimension
Q. What are the three subcategories of the physical dimension of the environment?
Answer: The three subcategories of the physical dimension of the environment are: (i) Lithospheric (solid) environment (ii) Hydrospheric (liquid) environment (iii) Atmospheric (gaseous) environment
Q. What does the lithospheric environment consist of?
Answer: The lithospheric environment is an abiotic component of the environment consisting of a thin layer of mantle, made up of soil and rocks, covering about 30% of the earth’s surface. It supports terrestrial life ranging from arid deserts to temperate and tropical rainforests.
Q. What proportion of the Earth’s surface is covered by the lithosphere?
Answer: The lithosphere covers about 30% of the earth’s surface.
Q. What does the hydrospheric environment include?
Answer: The hydrospheric environment is an abiotic component of the environment that includes the earth’s water present in oceans, rivers, lakes, soil, and as water vapours in the atmosphere. It covers more than two-thirds of the Earth’s surface.
Q. What percentage of the Earth’s water is contained in the oceans?
Answer: The greatest volume of Earth’s water, 97.2%, is contained in the oceans.
Q. How does water change states on Earth?
Answer: The physical conditions on the Earth’s surface ensure that water can exist in all three states. Temperature or pressure changes water from one state to another, such as in winter when water in ponds can freeze into solid ice, or in summer when it can evaporate.
Q. What environmental conditions can lead to the formation of violent storms?
Answer: Violent storms, such as cyclones, hurricanes, and tsunamis, can form when powerful winds drag along the surface water of the sea, causing waves and turbulence.
Q. What gases primarily make up the Earth’s atmosphere?
Answer: The Earth’s atmosphere is primarily composed of nitrogen (78%) and oxygen (21%).
Q. What role do different layers of the atmosphere play?
Answer: Different layers of the atmosphere, such as the troposphere, stratosphere, mesosphere, and ionosphere, protect us from harmful rays, meteoroids, and help maintain a suitable climate for the survival of life on Earth.
Q. What is the impact of chlorofluorocarbons (CFCs) on the environment?
Answer: Chlorofluorocarbons (CFCs) are chemicals that are damaging the ozone layer, contributing to changes in the atmospheric conditions, such as global warming and climate change.
Q. What is another name for the Biological Dimension of the environment?
Answer: The Biological Dimension of the environment is also known as the biotic dimension of the environment.
Q. What does the biotic dimension of the environment consist of?
Answer: The biotic dimension of the environment consists of flora or plant environment and fauna or animal environment. It includes all living organisms that interact with each other and with the abiotic components.
Q. What forms the largest and almost self-sufficient biological system on Earth?
Answer: Earth’s living organisms interacting with their physical or abiotic environment (including air, land, and water) form a giant and vast ecosystem called the ecosphere or biosphere, which is the largest and almost self-sufficient biological system.
Q. How many types of organisms are in the biotic environment?
Answer: The organisms in the biotic or biological environment are mainly of three types: Producers, Consumers, and Decomposers.
Q. Who are the producers in the biotic environment?
Answer: Producers are mainly green plants and photosynthetic bacteria. They aid in fixing radiant energy of the sun and with the help of minerals gained from mud and water. They also manufacture complex organic substances such as carbohydrates, proteins, and lipids.
Q. Who are the consumers in the biotic environment?
Answer: Consumers are heterotrophs that depend for their nutrition on the organic food manufactured by producers, the green plants. All types of animals, including humans, are consumers because they depend on plants (producers) for their food.
Q. Who are the decomposers in the biotic environment?
Answer: Decomposers are also called microconsumers. This term is used as they absorb only a fraction of decomposed organic matter. They bring about the decomposition of dead organic matter of both plants and animals. They help in returning mineral elements again to the medium of the pond and in running biogeochemical cycles.
Q. What does the floral environment consist of?
Answer: The floral environment consists of the flora, which means all the plant life normally present in a given habitat at a given time.
Q. How has human development impacted the floral environment?
Answer: Floral environment has taken the brunt of human development in many ways. Increasing numbers of human beings are encroaching on remaining wild lands, even in those areas once considered relatively safe from exploitation, degradation, and pollution.
Q. What was the rate of deforestation in the Amazon Basin area in 1993 according to satellite data?
Answer: In 1993, satellite data provided a rate of 5,800 square miles a year in the Amazon Basin area alone.
Q. What is the consequence of tropical deforestation if it continues unchecked?
Answer: Tropical deforestation has already resulted in the extinction of as many as 750,000 species and is likely to eliminate millions more if allowed to continue unchecked. This would mean the loss of a multiplicity of products, including food, fibres, medical drugs, dyes, gums, and resins.
Q. What are the main threats to tropical forests, especially in Southeast Asia and the Amazon river basin?
Answer: Tropical forests, especially in Southeast Asia and the Amazon river basin, are being destroyed at an alarming rate for timber, conversion to crop and grazing lands, pine plantations, and settlements.
Q. What does the faunal environment consist of?
Answer: The faunal environment consists of the fauna, which means all the animal life normally present in a given habitat at a given time.
Q. What has been the impact of human activities on the natural distribution of wildlife?
Answer: The natural distribution of wildlife has been changing in recent times due to human activities. Wherever man goes, he takes his gun and his dog along, and uninvited guests like rats and lice also follow him. His thoughtless killings and the introduction of new animals to a region have led to unforeseen consequences and changes in the natural distribution in a region.
Q. What can happen when an animal is introduced to a place where its controlling organisms are lacking?
Answer: When an animal is introduced to a place where its controlling organisms are lacking, it multiplies unchecked. For example, settlers introduced the rabbit to Australia, and having no natural enemies, the rabbits soon overran the countryside, destroying millions of acres of pasture.
Q. How does human travel contribute to the spread of diseases?
Answer: Some diseases are carried from place to place as a result of human travel. Plant diseases newly brought to an island or continent may cause the death of many native plants. As a result, animals that depend on those plants also disappear.
Q. What are the threats to wild areas in Nagaland?
Answer: In Nagaland, wild areas are being threatened by agricultural expansion, industries, and widespread pollution. Without concerted efforts to protect habitats and reduce poaching and the illegal worldwide wildlife trade, many wildlife species will become extinct.
Q. What do all organisms in the floral or faunal environment work to form?
Answer: All the organisms in the floral or faunal environment work to form their social groups and organisations at several levels and thus form the social environment wherein the organisms work to derive matter from the physical environment for their sustenance and development.
Q. What process generates the economic environment?
Answer: The process of organisms deriving matter from the physical environment for their sustenance and development generates the economic environment.
Q. Which organism is considered the most skilled and civilised?
Answer: It may be observed that amongst all organisms, human beings are the most skilled and civilised.
Q. What is vital to note about the physical, social, and economic aspects of human beings?
Answer: It is vital to note that each physical, social, and economic aspect of human beings has its unique importance, characteristics, and function in relation to the biotic environment.
Q. What does the physical man, as part of the biological community, require from the physical environment?
Answer: The physical man, who is a part of the organismic inhabitants (biological community), needs basic elements of the physical environment, viz., space (habitat), food, air, water, and he also releases wastes into the ecosystem like other members of the biological population.
Q. What does the social man create and establish?
Answer: The social man tends to create social institutions, establishes social organisations, makes laws, policies, and principles to protect his very own existence, interest, and social welfare.
Q. What does the economic man do with resources from the physical and biotic environments?
Answer: The economic man tends to derive and use the resources from the physical and biotic environments with his skills and technologies. He is the one who transports matter and energy from one component of the ecosystem to the other.
Q. What happens when the exploitation of resources exceeds the critical limit?
Answer: When exploitation increases the critical limit, the balance of the environment gets disturbed, and various environmental or ecological problems occur. These problems prove detrimental to human beings as well as all other members of the environment.
Q. What is the environmental outlook for the future?
Answer: The environmental outlook for the future is mixed. In spite of economic and political changes, interest in and concern about the environment remains high. To reduce environmental degradation and for humanity to save its habitats, societies must recognise that the environment is finite.
Q. What do environmentalists believe about continuous growth and sustainable exploitation?
Answer: Environmentalists believe that, as population and their demands increase, the idea of continuous growth must give way to a more rational use and sustainable exploitation of the environment.
Q. What must humanity recognise to save the environment?
Answer: Humanity should recognise that the human attack on the environment threatens human survival, and a dramatic change in attitude is needed to prevent this.
Q. What is the abiotic component of the lithospheric environment?
Answer: Lithospheric Environment: An abiotic component of environment consisting of a thin mantle of soil that supports terrestrial life.
Q. What does the hydrospheric environment consist of?
Answer: Hydrospheric Environment: An abiotic component of the environment consisting of the Earth’s water present in the oceans, rivers, lakes, atmosphere, and soil.
Q. What is the atmospheric environment and its significance?
Answer: Atmospheric Environment: An abiotic component of the environment that protects the Earth from ultraviolet radiation and is a gaseous mixture of nitrogen, oxygen, hydrogen, carbon dioxide, and water vapour.
Q. What is the biosphere?
Answer: Biosphere: The whole of the region of the Earth’s surface, the sea, and the air that is inhabited by living organisms.
Q. What does the term ‘biotic’ refer to?
Answer: Biotic: A part of the biological dimension of the environment consisting of living elements.
Q. What is flora?
Answer: Flora is all the plant life normally present in a given habitat at a given time.
Q. What is fauna?
Answer: Fauna is all the animal life normally present in a given habitat at a given time.
Q. What is the general perception of the environment according to the chapter summary?
Answer: Environment is mostly equated with nature. It is the sum total of conditions which surround man at a given point in space and time.
Q. How are the dimensions of the environment categorized?
Answer: The dimensions of the environment are physical, biological, and cultural or social. The physical dimensions of the environment can be divided into lithospheric, hydrospheric, and atmospheric. The biological dimensions of the environment are divided into floral and faunal environments.
Q. What does the social or cultural or man-made environment consist of?
Answer: The social or cultural or man-made environment consists of physical, social, and economic spheres.
Q. What is the lithospheric environment and its significance?
Answer: The lithospheric (solid) environment covers about 30% of the Earth’s surface. It is an abiotic component of the environment consisting of a thin layer of mantle made up of soil and rocks. The lithosphere supports terrestrial life, ranging from arid deserts to temperate forests and tropical rainforests. The conditions for life on land vary more significantly than in other environmental conditions.
Q. Describe the atmospheric environment and its role in sustaining life on Earth.
Answer: The atmospheric (gaseous) environment is a blanket of air surrounding the Earth, composed mainly of nitrogen (78%) and oxygen (21%). The atmosphere contains different layers of gases that protect life on Earth from harmful radiations of the sun. However, atmospheric conditions are changing due to large-scale forest clearance, industrial development, and the release of greenhouse gases, leading to global warming and climate change. Certain chemicals, like chlorofluorocarbons (CFCs), are damaging the ozone layer, which is crucial for protecting life from harmful rays and maintaining a suitable climate. The atmosphere’s layers, including the troposphere, stratosphere, mesosphere, and ionosphere, play vital roles in sustaining life by protecting against harmful rays and meteoroids.
Q. What are producers in the biological environment?
Answer: Producers are mainly green plants and photosynthetic bacteria. They aid in fixing the radiant energy of the sun and, with the help of minerals gained from mud and water, manufacture complex organic substances such as carbohydrates, proteins, and lipids.
Q. What are consumers in the biological environment?
Answer: Consumers are heterotrophs that depend for their nutrition on the organic food manufactured by producers, the green plants. All types of animals, including humans, are consumers because they depend on plants (producers) for their food.
Q. What are decomposers, and what role do they play in the environment?
Answer: Decomposers, also called microconsumers, absorb only a fraction of decomposed organic matter. They bring about the decomposition of dead organic matter from both plants and animals. Decomposers help in returning mineral elements to the medium of the pond and in running biogeochemical cycles.
Q. What distinguishes human beings in the context of social organisation?
Answer: Amongst all organisms, the human being is the most skilled and civilised. This makes his social organisation rather systematic. It is vital to note that each physical, social, and economic aspect of human beings has its unique importance, characteristics, and function in relation to the biotic environment.
Q. What is the role of the ‘social man’ in human society?
Answer: The social man tends to create social institutions, establishes social organisations, and makes laws, policies, and principles to protect his very own existence, interest, and social welfare.
Q. What is the function of the ‘economic man’ in the environment?
Answer: The economic man tends to derive and use the resources from the physical and biotic environments with his skills and technologies. He is the one who transports matter and energy from one component of the ecosystem to the other. This function does not cause change in the ecosystem as long as its exploitation is in coordination with the natural environment. However, when exploitation exceeds the critical limit, the balance of the environment gets disturbed, leading to various environmental or ecological problems.
Q. What are the consequences of the ‘economic man’s’ excessive exploitation of resources?
Answer: When the exploitation of resources by the economic man exceeds the critical limit, the balance of the environment gets disturbed, and various environmental or ecological problems occur. These problems prove detrimental to human beings as well as all other members of the environment.
Q. What is the outlook on the environment for the future?
Answer: The environmental outlook for the future is mixed. In spite of economic and political changes, interest in and concern about the environment remains high. To reduce environmental degradation and for humanity to save its habitats, societies must recognise that the environment is finite.
Q. How does the hydrospheric environment contribute to the Earth’s ecosystem?
Answer: The hydrospheric (liquid) environment covers more than two-thirds of the Earth’s surface. It is an abiotic component of the environment consisting of the Earth’s water, present in oceans, rivers, lakes, soil, and as water vapours in the atmosphere. The greatest volume of this water—97.2%—is contained in oceans, with the remainder forming fresh water, ice, and water vapour. The physical conditions on Earth allow water to exist in all three states: solid, liquid, and gas. This versatility enables water to play a crucial role in various natural processes, such as the water cycle, which is vital for maintaining life on Earth.
Q. What role does the atmospheric environment play in sustaining life on Earth?
Answer: The atmospheric (gaseous) environment is a blanket of air surrounding the Earth, consisting mainly of nitrogen (78%) and oxygen (21%). The atmosphere’s different layers protect us from various harmful radiations of the sun. However, atmospheric conditions are changing due to large-scale forest clearance, industrial development, and the release of greenhouse gases. These changes are contributing to global warming, which is altering the global climate. Moreover, certain widely used chemicals, like chlorofluorocarbons (CFCs), are damaging the ozone layer. The atmosphere’s layers—troposphere, stratosphere, mesosphere, and ionosphere—protect us from harmful rays, meteoroids, and help maintain a suitable climate for life on Earth.
Q. What constitutes the biological dimension of the environment?
Answer: The biological dimension of the environment, also referred to as the biotic dimension, consists of flora (plant environment) and fauna (animal environment). It encompasses all living organisms, which are collectively known as the biotic components of the environment. These organisms interact not only with each other but also with the non-living, or abiotic, components such as air, land, and water. Together, these interactions form a vast ecosystem known as the ecosphere or biosphere, which is the largest and nearly self-sufficient biological system on Earth. This dimension is vital as it includes producers, consumers, and decomposers, each playing a crucial role in maintaining the balance of the ecosystem.
Q. What is the significance of decomposers in the ecosystem?
Answer: Decomposers, also known as microconsumers, play a significant role in the ecosystem by breaking down dead organic matter from both plants and animals. Unlike other consumers, they absorb only a fraction of the decomposed organic material. This decomposition process is vital as it recycles nutrients back into the environment, particularly returning mineral elements to the soil and water bodies. This function helps maintain the biogeochemical cycles, ensuring that the ecosystem remains balanced and sustainable. Without decomposers, dead organic matter would accumulate, leading to a disruption in the nutrient cycles and the overall functioning of the ecosystem.
Q. How does the floral environment in Nagaland reflect its biodiversity?
Answer: Nagaland, despite being a small state, showcases a rich and varied heritage of biodiversity due to its unique geographic location and the wide range of physiographic terrains present. The floral environment in Nagaland is characterized by a diverse array of forest types, ranging from tropical rainforests to alpine vegetation, and from evergreen forests to sub-tropical climatic regions. This diversity in vegetation supports a wide variety of plant species, making the floral environment in Nagaland particularly rich. However, human activities such as deforestation and encroachment pose significant threats to this biodiversity, leading to the loss of plant species and, consequently, the fauna that depends on them.
Q. What are the major threats to the floral environment due to human activities?
Answer: The floral environment has faced significant challenges due to human activities, particularly the insatiable demand for land and resources. Large-scale deforestation, driven by the need for timber, agricultural expansion, and development, has resulted in the clearing of vast tracts of forest land. For example, in the 1980s, it was estimated that forest lands were being cleared at a rate of nearly 50 acres per minute. This rapid deforestation has led to the extinction of numerous species, with estimates suggesting that as many as 750,000 species have already been lost. Additionally, the development of Arctic regions for oil and gas exploration poses a threat to the delicate ecological balance of tundra ecosystems and their flora.
Q. What is the impact of introducing non-native animals to a new region?
Answer: Introducing non-native animals to a new region can have unforeseen and often devastating effects on the local ecosystem. For example, when settlers introduced rabbits to Australia, the absence of natural predators allowed the rabbit population to explode, leading to the destruction of millions of acres of pasture. Such unchecked multiplication of non-native species can disrupt the natural balance, as the controlling organisms (predators, parasites) that would normally keep their numbers in check are absent in the new environment. This can result in the displacement or extinction of native species, as the introduced species compete for resources or prey on the native fauna.
73. What are the consequences of tropical deforestation?
Answer: Tropical deforestation has far-reaching and devastating consequences for both the environment and biodiversity. As forests are cleared at an alarming rate—estimated at 200,000 square kilometers per year in the 1980s—numerous species face extinction. In the Amazon Basin alone, satellite data from 1993 indicated a deforestation rate of 5,800 square miles per year. This loss of forest habitat has already led to the extinction of as many as 750,000 species, with millions more at risk if deforestation continues unchecked. The loss of tropical forests also means the depletion of a wide range of products such as food, fibers, medical drugs, dyes, gums, and resins, which are derived from forest resources.
