Basic Concept of Environment: AHSEC Class 11 Environmental

Leave a Comment

Get summay, questions, answers, solutions, notes, extras, PDF, competency-based questions of chapter- 1/unit- I, Basic Concept of Environment: AHSEC Class 11 Environmental Education, which is part of the present syllabus. These solutions, however, should only be treated as references and can be modified/changed. 

Summary

The term environment refers to our surroundings. It includes the air, water, soil, and sunlight that all living things need to survive. The environment has both living parts, known as biotic components like plants and animals, and non-living parts, known as abiotic components. It also includes an energy component, which comes from sources like the sun. The environment provides the right conditions for life to exist and grow.

The environment is made of three main components. The abiotic, or non-living, component is divided into the lithosphere (solid ground), the hydrosphere (all water), and the atmosphere (the air). The biotic, or living, component includes all plants, animals, and people. The energy component includes solar power and other forms of energy. These parts work together in four major segments: the atmosphere, hydrosphere, lithosphere, and the biosphere, which is the special zone where all life is found.

The atmosphere is the layer of gases around the Earth. It acts like a protective blanket, which means it shields us from harmful things from outer space, such as cosmic rays. It is made mostly of nitrogen and oxygen. A part of the atmosphere called the stratosphere contains ozone gas. Ozone works like a protective shield, blocking dangerous ultraviolet radiation from the sun that can harm living things.

The hydrosphere is all the water on Earth, including oceans, rivers, lakes, and glaciers. A large part of our planet is covered in water, but most of it is salty ocean water. Only a very small amount is fresh water that is available for us to use. The lithosphere is the solid, outer part of the Earth, made of minerals and soil. Soil is very important as it provides minerals for plants and is home to many organisms.

In recent times, human activities have caused great harm to the environment. Things like pollution, cutting down forests, and a growing population have created serious problems. This is why environmental education is so important. It helps people understand their relationship with the natural world and the problems it faces. Education teaches us to be aware and to care for our surroundings. It provides the knowledge needed to solve environmental challenges. It uses information from many fields of study because the environment is very complex. Understanding that our actions today affect the future is the first step toward protecting our planet for generations to come.

Textual/Exercise

1. What is environment ?

Answer: The term environment means surroundings. It comes from the French word environner, which means to encircle or to surround. It is a composite term for the conditions in which organisms live and thus consists of air, water, soil, and sunlight, which are the basic needs of all living beings and plant life to carry on their life functions. The environment also includes temperature, wind, energy, and so on. Thus, it consists of both biotic and abiotic components.

2. What are the different components of the environment ?

Answer: The environment consists of the following three components:

• Abiotic component or non-living component
• Biotic component or living component
• Energy component

The abiotic or physical environment is subdivided into three categories:

• Lithosphere (solid)
• Hydrosphere (liquid)
• Atmosphere (gas)

The biotic component consists of flora and fauna including man. The energy component includes solar energy, geothermal energy, hydroelectrical energy, atomic energy, etc.

3. What are the different segments of the environment ?

Answer: There are four segments of the environment:

• Atmosphere
• Hydrosphere
• Lithosphere
• Biosphere

4. Mention the major components of the atmosphere.

Answer: The major components of the atmosphere are:

• Nitrogen, N₂ (78.09 %)
• Oxygen, O₂ (20.94 %)

5. What is the role of ozone present in the stratosphere ?

Answer: The ozone (O₃) present in the stratosphere plays an important role for us. It acts as a protective shield for life on earth from the injurious effects of the sun’s ultra violet radiations.

6. What do you mean by environmental education ?

Answer: Environmental education is education through the environment, about the environment, and for the environment. It is the educational process dealing with man’s relationship with his natural and man-made surroundings and includes the relation of population, pollution, resource allocation and depletion, conservation, transportation technology, and urban and rural planning to the total human environment. Environmental education is also the process of recognizing values and clarifying concepts in order to develop skills and attitudes necessary to understand and appreciate the interrelatedness among man, his culture, and his biophysical surroundings.

7. What are the broad guidelines of environmental education ?

Answer: The broad guidelines for environmental education, as decreed by the declaration from the first intergovernmental conference on environmental education held at Tbilisi (USSR, 1977), state that environmental education should:

• be interdisciplinary in its approach
• consider the holistic environment
• be continuous, beginning at preschool level and continuing through all the formal and non formal stages
• examine the major environmental issues critically from the local, regional, national and international points of view
• consider the current and future environmental trends and scenario
• help learners discover the symptoms and real causes of environmental problems and plan accordingly
• finally strive to promote the value and necessity of local, national and international cooperation in solving environmental problems.

8. Mention the basic principles of environmental education.

Answer: The objectives and the guiding principles for environmental education are:

• Awareness and sensitivity to the environment and environmental challenges
• Knowledge and understanding of the environment and environmental challenges
• Attitude of concern for the environment and motivation to improve or maintain environmental quality
• Skills to identify and help resolve environmental challenges
• Participation in activities that lead to the resolution of environmental challenges.

9. Discuss the multidisciplinary nature of environmental education.

Answer: Environmental education is a multidisciplinary subject. In order to know the environment and its different complex phenomena, one requires knowledge from various disciplines. Subjects like botany, zoology, biotechnology, bioengineering, microbiology, genetics, biochemistry etc. help in understanding biotic components and their interactions. The basic knowledge of physics, chemistry, mathematics, and statistics help in understanding the different phenomena in the environment. Computer science and information technology is a part and parcel of environmental education.

Similarly, for control of pollution, environmental engineering is essential. Other branches of engineering e.g. chemical, civil, mechanical including new innovative technologies have been involved in protecting the environment. Green chemistry finds its distinct and well specific role in protecting the degraded environment. Subjects like sociology, economics, education, and philosophy are involved in a number of ways. Environmental laws are always enacted for the protection of the environment. So environmental education carries the multidisciplinary nature where different aspects are dealt with a holistic approach.

10. How do environmental awareness help to protect our environment ?

Answer: Creation of public awareness is a must to protect the environment from further deterioration. Environmental problems can be best addressed if the people become environmentally aware. No Government can solve these problems by simply implementing certain environmental protection rules if people are not co-operating. People are to be environmentally educated. They should be able to learn that if we degrade our environment today, we will have to suffer tomorrow and our future generation will be in great danger. We are a part of the environment and it is our duty to protect it.

Extra/additional questions and answers

1. What does the term ‘environment’ mean?

Answer: The term ‘environment’ means surroundings. It is a composite term for the conditions in which organisms live and consists of air, water, soil, and sunlight.

2. What does the French word ‘environner’ mean?

Answer: The French word ‘environner’ means to encircle or to surround.

3. What are the two main types of components in the environment?

Answer: The two main types of components in the environment are the biotic and abiotic components.

4. What are the three main components of the environment?

Answer: The three main components of the environment are the abiotic component or non-living component, the biotic component or living component, and the energy component.

5. Name the three categories of the abiotic environment.

Answer: The three categories of the abiotic or physical environment are the Lithosphere, which is solid; the Hydrosphere, which is liquid; and the Atmosphere, which is gas.

6. What does the lithosphere represent?

Answer: The lithosphere represents the solid part of the abiotic environment. It is the outer mantle of the solid earth, consisting of minerals and soil.

7. What does the atmosphere represent?

Answer: The atmosphere represents the gas part of the abiotic environment. It is the protective blanket of gases that surrounds the earth and sustains life.

8. What does the biotic component of the environment consist of?

Answer: The biotic component of the environment consists of flora and fauna, including man.

9. Name any two types of energy included in the energy component.

Answer: Two types of energy included in the energy component are solar energy and geothermal energy.

10. Name the four segments of the environment.

Answer: The four segments of the environment are the Atmosphere, Hydrosphere, Lithosphere, and Biosphere.

11. What are the two major components of the atmosphere?

Answer: The two major components of the atmosphere are Nitrogen (N₂) and Oxygen (O₂).

12. Name the two minor components of the atmosphere.

Answer: The two minor components of the atmosphere are Argon (Ar) and Carbon dioxide (CO₂).

13. Name any four trace gases found in the atmosphere.

Answer: Four trace gases found in the atmosphere are neon, helium, methane, and water vapour.

14. What is the Troposphere?

Answer: The Troposphere is a region of the atmosphere with an altitude range of 0 to 11 km and a temperature range of 15 to –56 °C. The important chemical species found in this region are N₂, O₂, CO₂, and H₂O.

15. What is the Stratosphere?

Answer: The Stratosphere is a region of the atmosphere with an altitude range of 11 to 50 km and a temperature range of –56 to –2 °C. The important chemical species in this region is O₃, or ozone. The ozone present in the stratosphere acts as a protective shield for life on earth from the injurious effects of the sun’s ultra violet radiations.

16. What is the Mesosphere?

Answer: The Mesosphere is a region of the atmosphere with an altitude range of 50 to 85 km and a temperature range of –2 to –92 °C. The important chemical species found in this region are O₂⁺ and NO⁺.

17. What is the Thermosphere?

Answer: The Thermosphere is a region of the atmosphere with an altitude range of 85 to 500 km and a temperature range of –92 to 1200 °C. The important chemical species found in this region are O₂⁺, O⁺, and NO⁺.

18. What is the Hydrosphere?

Answer: The hydrosphere includes all types of water resources – oceans, seas, rivers, lakes, reservoirs, glaciers, polar icecaps and ground water, which is water below the earth’s surface. Earth is flooded with water, and a total volume of about 1400 million cubic kilometres covers 71% of the earth’s surface.

19. What percentage of the Earth’s surface is covered by water?

Answer: 71% of the Earth’s surface is covered by water.

20. What percentage of the Earth’s water is fresh water?

Answer: Only 3% of the Earth’s water is fresh water.

21. What percentage of fresh water is locked in polar icecaps and glaciers?

Answer: 79% of the Earth’s fresh water is locked in polar icecaps and glaciers.

22. What is the extent of the biosphere up into the atmosphere?

Answer: The biosphere extends about 6 to 8 kilometers up into the atmosphere.

23. When and where was the first intergovernmental conference on environmental education held?

Answer: The first intergovernmental conference on environmental education was held in 1977 at Tbilisi in the USSR.

24. Why is the Earth’s atmosphere unique and important for supporting life?

Answer: The Earth’s atmosphere is unique because it makes our planet the only one in the solar system capable of supporting life. It is a protective blanket of gases that sustains life and saves it from the hostile environment of outer space. It is important because it absorbs most cosmic rays, a major portion of electromagnetic radiation from the sun, and filters out tissue-damaging ultraviolet radiations.

25. List the major and minor components of the atmosphere with their respective percentages.

Answer: The major components of the atmosphere are Nitrogen (N₂), which makes up 78.09%, and Oxygen (O₂), which makes up 20.94%.

The minor components include Argon (Ar) at 9.34 x 10⁻¹% and Carbon dioxide (CO₂) at 3.25 x 10⁻² %. Other trace gases include neon, helium, methane, and water vapour.

26. Why did environmental degradation accelerate after the primitive days?

Answer: In primitive days, the population was small and the needs of man were limited, so the harmony with nature was not disturbed. In subsequent years, the population increased greatly. Science and technological advancement accelerated, and in the attempt to make life more comfortable, man began to destroy forests, pollute air and water, and spoil nature, which led to environmental degradation.

27. What is the role of education in addressing the environmental crisis?

Answer: Any solution to the environmental crisis requires environmental awareness and a clear understanding of the problem. The answer to this need is Environmental Education. Education plays a vital role in creating a healthy attitude, developing skills, and spreading knowledge necessary to address environmental issues.

28. Why is environmental education considered a multidisciplinary subject?

Answer: Environmental education is considered a multidisciplinary subject because in order to know the environment and its different complex phenomena, one requires knowledge from various disciplines. Subjects like botany and zoology help in understanding biotic components, while physics and chemistry help in understanding different phenomena in the environment.

29. What is the atmosphere? Discuss its composition and its role in sustaining life on Earth.

Answer: The atmosphere is the protective blanket of gases surrounding the Earth that sustains life and saves it from the hostile environment of outer space. It plays a key role in maintaining the heat balance of the Earth by absorbing infrared radiation from the sun and reemitted from the Earth. The atmosphere absorbs most cosmic rays and a major portion of electromagnetic radiation from the sun, filtering out tissue-damaging ultraviolet radiations. It is the source of oxygen, which is essential for life, and carbon dioxide, which is essential for plant photosynthesis. It also supplies nitrogen to yield chemically bound nitrogen, or protein, which is essential for life.

The composition of the atmosphere includes major components, minor components, and trace gases. The major components are Nitrogen (N₂), making up 78.09%, and Oxygen (O₂), at 20.94%. The minor components are Argon (Ar) at 9.34 x 10⁻¹% and Carbon dioxide (CO₂) at 3.25 x 10⁻²%. Trace gases include neon, helium, methane, water vapour, krypton, nitrous oxide, xenon, hydrogen, sulphur dioxide, ozone, ammonia, carbon monoxide, and nitrogen dioxide.

30. Describe the four regions into which the atmosphere is broadly classified.

Answer: The atmosphere is broadly classified into four distinct regions based on altitude and temperature.

The first region is the Troposphere, which extends from 0 to 11 km in altitude. The temperature in this region ranges from 15°C to -56°C. The important chemical species found here are Nitrogen (N₂), Oxygen (O₂), Carbon Dioxide (CO₂), and Water (H₂O).

The second region is the Stratosphere, located at an altitude range of 11 to 50 km. Its temperature ranges from -56°C to -2°C. The most important chemical species in this layer is Ozone (O₃), which acts as a protective shield against the sun’s ultraviolet radiation.

The third region is the Mesosphere, which spans from 50 to 85 km in altitude. The temperature here ranges from -2°C to -92°C. The important chemical species present are ionized oxygen (O₂⁺) and nitric oxide ions (NO⁺).

The fourth region is the Thermosphere, extending from an altitude of 85 km to 500 km. The temperature in this region increases significantly, ranging from -92°C to 1200°C. The important chemical species include ionized oxygen (O₂⁺), atomic oxygen ions (O⁺), and nitric oxide ions (NO⁺).

31. What is the hydrosphere? Explain the distribution of water on Earth and the availability of fresh water for human use.

Answer: The hydrosphere includes all types of water resources on Earth. These resources are oceans, seas, rivers, lakes, reservoirs, glaciers, polar icecaps, and groundwater, which is water found below the Earth’s surface. The Earth is covered with a total volume of about 1400 million cubic kilometres of water, which covers 71% of the planet’s surface.

Despite the large amount of water, only a small fraction is available as fresh water for human use. About 97% of the Earth’s total water supply is in the ocean, which is unfit for human consumption and other uses because of its salinity. Only 3% of the Earth’s water is fresh water. Of this 3%, 79% is locked in polar icecaps and glaciers, and 20% is locked as underground water. This leaves only 1% of the total freshwater, which is found in rivers, lakes, streams, and reservoirs, readily available for direct human use.

32. Distinguish between Biotic and Abiotic components of the environment?

Answer: The biotic component of the environment is the living component, which consists of flora and fauna including man.

On the other hand, the abiotic component is the non-living component. The abiotic or physical environment is subdivided into three categories:

• Lithosphere (solid)
• Hydrosphere (liquid)
• Atmosphere (gas)

33. Distinguish between the Lithosphere and the Hydrosphere?

Answer: The Lithosphere is the outer mantle of the solid earth consisting of minerals and soil. Soil comprises a complex mixture of minerals, organic matters, air and water. The soil is the most important part of the lithosphere and is a storehouse of minerals, a reservoir of water, a conserver of soil fertility, a producer of crops, and a home for wildlife and livestock.

The Hydrosphere, on the other hand, includes all types of water resources such as oceans, seas, rivers, lakes, reservoirs, glaciers, polar icecaps, and groundwater, which is water below the earth’s surface.

34. Distinguish between the Hydrosphere and the Atmosphere?

Answer: The Hydrosphere includes all types of water resources, such as oceans, seas, rivers, lakes, reservoirs, glaciers, polar icecaps, and groundwater. It represents the liquid component of the environment.

The Atmosphere is the protective blanket of gases surrounding the earth which sustains life on earth and saves it from the hostile environment of the outer space. It represents the gas component of the environment.

35. Distinguish between the Atmosphere and the Biosphere?

Answer: The Atmosphere is the protective blanket of gases surrounding the earth. It is the source of oxygen and carbon dioxide, which are essential for life and photosynthesis.

The Biosphere is the layer on the earth in which life can exist. This layer extends about 6 – 8 km up into the atmosphere and as much as 8 – 10 km below into the depth of the sea. It denotes the realm of living organisms and their interactions with the environment, which includes the atmosphere, hydrosphere, and lithosphere.

36. Distinguish between the Troposphere and the Stratosphere?

Answer: The Troposphere and the Stratosphere are distinguished based on their altitude, temperature range, and important chemical species:

37. Distinguish between the Stratosphere and the Mesosphere?

Answer: The Stratosphere and the Mesosphere are distinguished based on their altitude, temperature range, and important chemical species:

38. Distinguish between the Mesosphere and the Thermosphere?

Answer: The Mesosphere and the Thermosphere are distinguished based on their altitude, temperature range, and important chemical species:

Region	Altitude range (Km)	Temp. range (°C)	Important chemical species
Mesosphere	50 – 85	–2 to –92	O₂⁺, NO⁺
Thermosphere	85 – 500	–92 to 1200	O₂⁺, O⁺, NO⁺

Extra/additional Fill in the Blanks

1. The term environment comes from the French word ______.

Answer: environner

2. The abiotic or physical environment is subdivided into three categories: Lithosphere, Hydrosphere, and ______.

Answer: Atmosphere

3. The biotic component of the environment consists of flora and ______ including man.

Answer: fauna

4. The energy component of the environment includes solar energy, geothermal energy, hydroelectrical energy, and ______ energy.

Answer: atomic

5. There are four segments of the environment: Atmosphere, Hydrosphere, Lithosphere, and ______.

Answer: Biosphere

6. The atmosphere filters out tissue damaging ______ radiations from the sun.

Answer: ultra violet

7. Nitrogen makes up ______% of the atmosphere’s composition.

Answer: 78.09

8. Oxygen makes up ______% of the atmosphere’s composition.

Answer: 20.94

9. Gases like neon, helium, methane, and water vapour are considered ______ gases in the atmosphere.

Answer: trace

10. The atmosphere is the source of ______, which is essential for plant photosynthesis.

Answer: carbon dioxide

11. The atmosphere may be broadly classified into ______ regions.

Answer: four

12. The altitude range of the Troposphere is ______ Km.

Answer: 0 – 11

13. The ozone (O₃) present in the ______ acts as a protective shield for life on earth.

Answer: stratosphere

14. The ______ includes all types of water resources – oceans, seas, rivers, lakes, reservoirs, glaciers, polar icecaps and ground water.

Answer: hydrosphere

15. About ______% of the earth’s surface is covered by water.

Answer: 71

16. About ______% of the earth’s water supply is in the ocean.

Answer: 97

17. Only ______% of the earth’s water is fresh water.

Answer: 3

18. The ______ is the outer mantle of the solid earth consisting of minerals and soil.

Answer: lithosphere

19. The ______ is the layer on the earth in which life can exist.

Answer: biosphere

20. The conference on human environment in ______ emphasized the need for environmentally oriented education.

Answer: 1972

21. The first intergovernmental conference of environmental education was held at ______ in 1977.

Answer: Tbilisi