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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%
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.
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.
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