NCERT Solution - Our Environment Class 10 Notes | EduRev

Created by: Navjeet Sandal

Class 10 : NCERT Solution - Our Environment Class 10 Notes | EduRev

 Page 1


Chapter: Our Environment 
     NCERT SOLUTIONS 
Q1: Define Ecology 
 
Answer: Ecology is a scientific study of the interactions between organisms and the environment. 
Ecology integrates all areas of biological research and informs environmental decision. 
 
Q2: What is the scope of Ecology Research? 
 
Answer: Ecology study can be broadly classified as: 
a. Organismal Ecology  
b. Population Ecology 
c. Community Ecology 
d. Ecosystem Ecology 
e. Landscape Ecology 
f. Global Ecology 
 
In nutshell, Ecology study advocates protection of nature and the environment. 
 
Q3: Define Ecosystem. 
 
Answer: An environment comprises of all living (biotic) and non-living (abiotic) things that occur 
naturally on the Earth or any of its region. All these living organisms interact with each other and their 
growth, reproduction and other activities are affected by the abiotic components of ecosystem. 
 
Q4: Is garden an example of Ecosystem? 
 
Answer: Yes. In an garden, all biotic components (e.g. plants, trees, animals like rats, frogs, birds, 
insects etc.) interact with each other and with abiotic components (garden soil, water etc.) for their 
growth and reproduction and other activities. Thus garden forms an ecosystem. 
 
Q5: Give examples of natural ecosystems. 
 
Answer: Forests, ponds, lakes, sea, oceans, coral reefs, rivers etc. 
 
Q6: Give examples of human made (artificial )ecosystems. 
 
Answer: Gardens, Crop-fields etc. 
 
 
 
Q7: Name different abiotic factors that affect the ecosystem. 
 
Answer: Temperature, water, sunlight, salinity, rocks, soil, precipitation and wind. 
 
Q8: What do you mean by biogeochemical cycle? Name examples of biogeochemical cycles 
exist in ecosystem. 
 
Answer: A biogeochemical cycle is a pathway by which a chemical element or molecule moves 
through both biotic and abiotic compartments of Earth. These are critical to life and hence for the 
ecosystem sustenance. A few examples of the biogeochemical cycles are: 
? Nitrogen Cycle  
? Water Cycle  
? Carbon Cycle  
? Oxygen Cycle  
? Phosphorus Cycle  
Page 2


Chapter: Our Environment 
     NCERT SOLUTIONS 
Q1: Define Ecology 
 
Answer: Ecology is a scientific study of the interactions between organisms and the environment. 
Ecology integrates all areas of biological research and informs environmental decision. 
 
Q2: What is the scope of Ecology Research? 
 
Answer: Ecology study can be broadly classified as: 
a. Organismal Ecology  
b. Population Ecology 
c. Community Ecology 
d. Ecosystem Ecology 
e. Landscape Ecology 
f. Global Ecology 
 
In nutshell, Ecology study advocates protection of nature and the environment. 
 
Q3: Define Ecosystem. 
 
Answer: An environment comprises of all living (biotic) and non-living (abiotic) things that occur 
naturally on the Earth or any of its region. All these living organisms interact with each other and their 
growth, reproduction and other activities are affected by the abiotic components of ecosystem. 
 
Q4: Is garden an example of Ecosystem? 
 
Answer: Yes. In an garden, all biotic components (e.g. plants, trees, animals like rats, frogs, birds, 
insects etc.) interact with each other and with abiotic components (garden soil, water etc.) for their 
growth and reproduction and other activities. Thus garden forms an ecosystem. 
 
Q5: Give examples of natural ecosystems. 
 
Answer: Forests, ponds, lakes, sea, oceans, coral reefs, rivers etc. 
 
Q6: Give examples of human made (artificial )ecosystems. 
 
Answer: Gardens, Crop-fields etc. 
 
 
 
Q7: Name different abiotic factors that affect the ecosystem. 
 
Answer: Temperature, water, sunlight, salinity, rocks, soil, precipitation and wind. 
 
Q8: What do you mean by biogeochemical cycle? Name examples of biogeochemical cycles 
exist in ecosystem. 
 
Answer: A biogeochemical cycle is a pathway by which a chemical element or molecule moves 
through both biotic and abiotic compartments of Earth. These are critical to life and hence for the 
ecosystem sustenance. A few examples of the biogeochemical cycles are: 
? Nitrogen Cycle  
? Water Cycle  
? Carbon Cycle  
? Oxygen Cycle  
? Phosphorus Cycle  
Q9: What do you mean by biosphere? 
 
Answer: Biosphere is the area on the earth where life exists. It includes about 20 kilometers upwards 
in the atmosphere and 11 kilometer downwards. In the Biosphere different plants and animals are 
present. This diversity of life is an important characteristic of earth. 
 
Q10: Define food chain. 
 
Answer: The pathway of transfer of food from one trophic level to another is known as food chain. 
 
Q11: What are trophic levels? 
 
 
Answer: Trophic levels are the feeding levels in an ecosystem. The trophic levels of living beings 
represent their placement in a food chain. It also tells the order of consumption and energy transfer 
throughout the ecosystem (or environment).  
In general 4 or 5 trophic levels exist in a food chain. These are: 
 
Producers or Autotrophs: Producers make up the first trophic levels that supports the other trophic 
levels. It consists mainly of green plants and certain types green algae and some types of bacteria. 
They convert solar energy (photosynthesis) into food consumable by other organisms. 
 
Primary Consumers: These are the consumers which feed upon producers. In general these are 
herbivores. Examples are horse, cow, deer, insects, zoo planktons (shrimps, protists etc.) and birds. 
 
Secondary Consumers: Secodnary or second level consumers eat primary consumers. In general 
these are omnivores and carnivores. On land, secondary consumers cover many small mammals and 
reptiles that eat insects, as well as large carnivores that eat rodents and grazing mammals. In aquatic 
ecosystems, secondary consumers are mainly small fish that eat plankton. 
 
Tertiary Consumers: These are third level consumers which feed on secondary consumers. E.g. 
snakes eating rodents, Lion, bear etc. 
 
Quanternary Consumers: Fourth level consumers are defined in a few food chains. E.g. hawks 
eating owls or snakes. 
All food chains end up with top predators, animals having little or no natural enemy. 
 
Q12: Define Dertivores 
 
Answer: Dertivores or Decomposers are the consumers that get energy from dead organic matter 
Page 3


Chapter: Our Environment 
     NCERT SOLUTIONS 
Q1: Define Ecology 
 
Answer: Ecology is a scientific study of the interactions between organisms and the environment. 
Ecology integrates all areas of biological research and informs environmental decision. 
 
Q2: What is the scope of Ecology Research? 
 
Answer: Ecology study can be broadly classified as: 
a. Organismal Ecology  
b. Population Ecology 
c. Community Ecology 
d. Ecosystem Ecology 
e. Landscape Ecology 
f. Global Ecology 
 
In nutshell, Ecology study advocates protection of nature and the environment. 
 
Q3: Define Ecosystem. 
 
Answer: An environment comprises of all living (biotic) and non-living (abiotic) things that occur 
naturally on the Earth or any of its region. All these living organisms interact with each other and their 
growth, reproduction and other activities are affected by the abiotic components of ecosystem. 
 
Q4: Is garden an example of Ecosystem? 
 
Answer: Yes. In an garden, all biotic components (e.g. plants, trees, animals like rats, frogs, birds, 
insects etc.) interact with each other and with abiotic components (garden soil, water etc.) for their 
growth and reproduction and other activities. Thus garden forms an ecosystem. 
 
Q5: Give examples of natural ecosystems. 
 
Answer: Forests, ponds, lakes, sea, oceans, coral reefs, rivers etc. 
 
Q6: Give examples of human made (artificial )ecosystems. 
 
Answer: Gardens, Crop-fields etc. 
 
 
 
Q7: Name different abiotic factors that affect the ecosystem. 
 
Answer: Temperature, water, sunlight, salinity, rocks, soil, precipitation and wind. 
 
Q8: What do you mean by biogeochemical cycle? Name examples of biogeochemical cycles 
exist in ecosystem. 
 
Answer: A biogeochemical cycle is a pathway by which a chemical element or molecule moves 
through both biotic and abiotic compartments of Earth. These are critical to life and hence for the 
ecosystem sustenance. A few examples of the biogeochemical cycles are: 
? Nitrogen Cycle  
? Water Cycle  
? Carbon Cycle  
? Oxygen Cycle  
? Phosphorus Cycle  
Q9: What do you mean by biosphere? 
 
Answer: Biosphere is the area on the earth where life exists. It includes about 20 kilometers upwards 
in the atmosphere and 11 kilometer downwards. In the Biosphere different plants and animals are 
present. This diversity of life is an important characteristic of earth. 
 
Q10: Define food chain. 
 
Answer: The pathway of transfer of food from one trophic level to another is known as food chain. 
 
Q11: What are trophic levels? 
 
 
Answer: Trophic levels are the feeding levels in an ecosystem. The trophic levels of living beings 
represent their placement in a food chain. It also tells the order of consumption and energy transfer 
throughout the ecosystem (or environment).  
In general 4 or 5 trophic levels exist in a food chain. These are: 
 
Producers or Autotrophs: Producers make up the first trophic levels that supports the other trophic 
levels. It consists mainly of green plants and certain types green algae and some types of bacteria. 
They convert solar energy (photosynthesis) into food consumable by other organisms. 
 
Primary Consumers: These are the consumers which feed upon producers. In general these are 
herbivores. Examples are horse, cow, deer, insects, zoo planktons (shrimps, protists etc.) and birds. 
 
Secondary Consumers: Secodnary or second level consumers eat primary consumers. In general 
these are omnivores and carnivores. On land, secondary consumers cover many small mammals and 
reptiles that eat insects, as well as large carnivores that eat rodents and grazing mammals. In aquatic 
ecosystems, secondary consumers are mainly small fish that eat plankton. 
 
Tertiary Consumers: These are third level consumers which feed on secondary consumers. E.g. 
snakes eating rodents, Lion, bear etc. 
 
Quanternary Consumers: Fourth level consumers are defined in a few food chains. E.g. hawks 
eating owls or snakes. 
All food chains end up with top predators, animals having little or no natural enemy. 
 
Q12: Define Dertivores 
 
Answer: Dertivores or Decomposers are the consumers that get energy from dead organic matter 
(detritus). Important groups of dertivores are prokaryotes and fungi. These organisms secrete 
enzymes to digest organic matter. They link the consumers and primary producers of an ecosystem. 
 
Q13: Explain energy relationship with trophic levels. 
 
Answer: The energy relation ship within trophic levels can be represented in a form of pyramid as 
shown in the figure. Following conclusions are arrived: 
 
a. In a biosphere, energy transfer takes place only through food chains. 
 
b. Each food chain can be considered as an energy chain. 
 
 
c. The energy that is captured by the autotrophs does not revert back to the solar input and the 
energy which passes to the herbivores does not come back to autotrophs. As it moves progressively 
through the various trophic levels it is no longer available to the previous level.  
 
d. Plants utilize only 50% of the total available energy for their life processes. But each of the trophic 
levels utilizes 90% of their available energy for their metabolic activities. Remaining 10% of the 
energy alone is transferred to the next trophic level. This is the reason long food chains are not 
commonly seen in nature. 
 
Q14: Explicate the principle of food web. 
 
Answer: Each organism is generally eaten by two or more other kinds of organisms which in turn are 
eaten by several other organisms. So instead of a straight line food chain, the relationship can be 
shown as a series of branching lines called a food web. 
 
Q15: Define biological magnification. 
 
Answer. It means accumulation of poisonous materials in successive trophic levels in a food chain. 
This happens when a toxin is ingested or eaten and moved up the food chain from one organism to 
another organism. As it moves up the food chain the toxin levels gets magnified or more 
concentrated. DDT is one example of harmful substance that have contaminated food chains. 
 
Q16: Explain Ozone depletion and its impact on our environment? 
Page 4


Chapter: Our Environment 
     NCERT SOLUTIONS 
Q1: Define Ecology 
 
Answer: Ecology is a scientific study of the interactions between organisms and the environment. 
Ecology integrates all areas of biological research and informs environmental decision. 
 
Q2: What is the scope of Ecology Research? 
 
Answer: Ecology study can be broadly classified as: 
a. Organismal Ecology  
b. Population Ecology 
c. Community Ecology 
d. Ecosystem Ecology 
e. Landscape Ecology 
f. Global Ecology 
 
In nutshell, Ecology study advocates protection of nature and the environment. 
 
Q3: Define Ecosystem. 
 
Answer: An environment comprises of all living (biotic) and non-living (abiotic) things that occur 
naturally on the Earth or any of its region. All these living organisms interact with each other and their 
growth, reproduction and other activities are affected by the abiotic components of ecosystem. 
 
Q4: Is garden an example of Ecosystem? 
 
Answer: Yes. In an garden, all biotic components (e.g. plants, trees, animals like rats, frogs, birds, 
insects etc.) interact with each other and with abiotic components (garden soil, water etc.) for their 
growth and reproduction and other activities. Thus garden forms an ecosystem. 
 
Q5: Give examples of natural ecosystems. 
 
Answer: Forests, ponds, lakes, sea, oceans, coral reefs, rivers etc. 
 
Q6: Give examples of human made (artificial )ecosystems. 
 
Answer: Gardens, Crop-fields etc. 
 
 
 
Q7: Name different abiotic factors that affect the ecosystem. 
 
Answer: Temperature, water, sunlight, salinity, rocks, soil, precipitation and wind. 
 
Q8: What do you mean by biogeochemical cycle? Name examples of biogeochemical cycles 
exist in ecosystem. 
 
Answer: A biogeochemical cycle is a pathway by which a chemical element or molecule moves 
through both biotic and abiotic compartments of Earth. These are critical to life and hence for the 
ecosystem sustenance. A few examples of the biogeochemical cycles are: 
? Nitrogen Cycle  
? Water Cycle  
? Carbon Cycle  
? Oxygen Cycle  
? Phosphorus Cycle  
Q9: What do you mean by biosphere? 
 
Answer: Biosphere is the area on the earth where life exists. It includes about 20 kilometers upwards 
in the atmosphere and 11 kilometer downwards. In the Biosphere different plants and animals are 
present. This diversity of life is an important characteristic of earth. 
 
Q10: Define food chain. 
 
Answer: The pathway of transfer of food from one trophic level to another is known as food chain. 
 
Q11: What are trophic levels? 
 
 
Answer: Trophic levels are the feeding levels in an ecosystem. The trophic levels of living beings 
represent their placement in a food chain. It also tells the order of consumption and energy transfer 
throughout the ecosystem (or environment).  
In general 4 or 5 trophic levels exist in a food chain. These are: 
 
Producers or Autotrophs: Producers make up the first trophic levels that supports the other trophic 
levels. It consists mainly of green plants and certain types green algae and some types of bacteria. 
They convert solar energy (photosynthesis) into food consumable by other organisms. 
 
Primary Consumers: These are the consumers which feed upon producers. In general these are 
herbivores. Examples are horse, cow, deer, insects, zoo planktons (shrimps, protists etc.) and birds. 
 
Secondary Consumers: Secodnary or second level consumers eat primary consumers. In general 
these are omnivores and carnivores. On land, secondary consumers cover many small mammals and 
reptiles that eat insects, as well as large carnivores that eat rodents and grazing mammals. In aquatic 
ecosystems, secondary consumers are mainly small fish that eat plankton. 
 
Tertiary Consumers: These are third level consumers which feed on secondary consumers. E.g. 
snakes eating rodents, Lion, bear etc. 
 
Quanternary Consumers: Fourth level consumers are defined in a few food chains. E.g. hawks 
eating owls or snakes. 
All food chains end up with top predators, animals having little or no natural enemy. 
 
Q12: Define Dertivores 
 
Answer: Dertivores or Decomposers are the consumers that get energy from dead organic matter 
(detritus). Important groups of dertivores are prokaryotes and fungi. These organisms secrete 
enzymes to digest organic matter. They link the consumers and primary producers of an ecosystem. 
 
Q13: Explain energy relationship with trophic levels. 
 
Answer: The energy relation ship within trophic levels can be represented in a form of pyramid as 
shown in the figure. Following conclusions are arrived: 
 
a. In a biosphere, energy transfer takes place only through food chains. 
 
b. Each food chain can be considered as an energy chain. 
 
 
c. The energy that is captured by the autotrophs does not revert back to the solar input and the 
energy which passes to the herbivores does not come back to autotrophs. As it moves progressively 
through the various trophic levels it is no longer available to the previous level.  
 
d. Plants utilize only 50% of the total available energy for their life processes. But each of the trophic 
levels utilizes 90% of their available energy for their metabolic activities. Remaining 10% of the 
energy alone is transferred to the next trophic level. This is the reason long food chains are not 
commonly seen in nature. 
 
Q14: Explicate the principle of food web. 
 
Answer: Each organism is generally eaten by two or more other kinds of organisms which in turn are 
eaten by several other organisms. So instead of a straight line food chain, the relationship can be 
shown as a series of branching lines called a food web. 
 
Q15: Define biological magnification. 
 
Answer. It means accumulation of poisonous materials in successive trophic levels in a food chain. 
This happens when a toxin is ingested or eaten and moved up the food chain from one organism to 
another organism. As it moves up the food chain the toxin levels gets magnified or more 
concentrated. DDT is one example of harmful substance that have contaminated food chains. 
 
Q16: Explain Ozone depletion and its impact on our environment? 
 
Ozone Depletion at Antartica 
 
Answer: Life on the Earth is protected from the damaging Ultra-violet radiation by a layer of ozone 
molecules $(O_3)$ The amount of ozone began to drop sharply in 1980. This decrease has been 
linked to synthetic chemicals like chrolo-fluoro-carbons (CFCs) which are used in refrigerants and in 
fire extinguisher.  
 
1. UV radiation causes a Chlorine atom to break away from CFC molecule. 
 
2. The free chlorine atoms hits on ozone molecule and pulls away one oxygen atom from it. 
 
3. A free oxygen atom hits the chlorine monoxide molecule which results another chlorine atom. 
4. In this way free chlorine will continue to delete ozone in stratosphere. One Chlorine atom can 
destroy more than 100,000 ozone molecules before it is removed from stratosphere. 
 
Decrease ozone levels in stratosphere increase the intensity of UV radiation. Its consequences can 
be very harmful and may lead to an increase in skin cancers and cataracts among humans. UV 
radiation are also harmful to crops and other primary producers and may lead to unpredictable 
results. 
 
Read More

Complete Syllabus of Class 10

Content Category

Related Searches

Extra Questions

,

Important questions

,

Previous Year Questions with Solutions

,

study material

,

Exam

,

ppt

,

NCERT Solution - Our Environment Class 10 Notes | EduRev

,

practice quizzes

,

shortcuts and tricks

,

pdf

,

Free

,

NCERT Solution - Our Environment Class 10 Notes | EduRev

,

Semester Notes

,

Objective type Questions

,

past year papers

,

video lectures

,

Viva Questions

,

mock tests for examination

,

Summary

,

MCQs

,

Sample Paper

,

NCERT Solution - Our Environment Class 10 Notes | EduRev

;