NCERT Solutions Class 10 Science Chapter 15

NCERT Solutions for Class 10 Science Chapter 15: Our Environment

Class 10 Science Chapter 15 is about- Our Environment. This is a critical chapter and carries a weightage of 3 marks in the CBSE Board Examination. This chapter covers several topics crucial to forming the basic knowledge about environmental science. . 

Extramarks is one of the leading  online educational platforms   for students. Our NCERT Solutions for Chapter 15 Class 10 Science is developed by subject matter experts  to help students understand all the basic to complex environmental  concepts with precise definitions, diagrams, and real-life examples. Concepts like constituents of air, wind, air present in the soil, the importance of oxygen for living organisms, and the importance of plants for survival and the atmosphere are well explained in the  NCERT Solutions for Class 10 Science Chapter 15.

Our NCERT Solutions are prepared  in such a way that the answers are self-explanatory, and will  clarify your doubts making  it easier to understand the concepts thoroughly and quickly. . You will find solutions to all the questions covered in NCERT textbook as per updated CBSE syllabus. The step by step methods of solving problems in the NCERT solutions facilitate students understand the concepts better while solving NCERT questions. Thus, enhancing their thought process and encouraging them to find answers to tricky and difficult questions.

Key Topics Covered In NCERT Solutions for Class 10 Science Chapter 15

The environment means everything which surrounds us. It includes living (biotic) things such as microorganisms, plants, animals, human beings, and non-living (abiotic) components such as weather, earth, sun, soil, climate, and atmosphere forming a balanced ecosystem. Environment affects the life and development of an organism. 

NCERT Solutions for Class 10 Science Chapter 15 discusses how various environmental components interact and how humans impact the environment.

Ecosystem and its Components:

This unit teaches about our surrounding nature, consisting of biotic (living) things like plants, human beings, and animals, and abiotic(non-living) things like air, soil, water, etc. These biotic and abiotic components live together and interact in a particular habitat to form a balanced ecosystem.

Structure of Ecosystem:

The ecosystem structure consists of two major components : 

  • Biotic components 
  • Abiotic components. 

It can be understood through the flow chart:

  1. Biotic Components:

As covered in the Class 10 Science NCERT Solutions Chapter 15, the biotic components consist of all living organisms such as plants, animals, microorganisms, and humans. These living organisms are classified into three groups below based on how they survive in the ecosystem.

  • Producers: Also known as Autotrophs. They are capable of producing their food using sunlight (Photosynthesis). Examples include All green plants and blue-green algae.
  • Consumers: Also known as Heterotrophs. The organisms depending on producers directly or indirectly for survival are grouped under Consumers. Consumers are further categorized as (i) Herbivorous: Grass Eaters, For Eg. Cow, deer (ii) Carnivorous: Flesh Eaters, for Eg. Lion Tiger (iii) Omnivorous: Feed on both plants and flesh, for Eg Dogs, Bears (iv) Parasite: Live & feed on the host body, for Eg. Plasmodium.
  • Decomposers: Microorganisms like bacteria and fungi break down/decompose complex organic compounds in dead plants and animals into simpler elementary substances like water, carbon dioxide, nitrogen, phosphorus, and calcium, which are used by plants to grow. Thus, they play a significant role in cycling the nutrients and replenishing the ecosystem’s natural resources.
  1. Abiotic Components:

The abiotic components include physical factors such as temperature, rainfall, wind, rocks, soil, minerals, water sources, and the local atmosphere. Like Biotic components, abiotic components also have their ecological role. For Example, elements and compounds like nitrogen, phosphorus, and calcium serve as sources of nutrients for living organisms. Apart from providing nutrients, they also provide organisms with a place to live and thrive – a habitat.

Types of Ecosystem

The two types of Ecosystems are:

  1. Man-made Ecosystem

These are artificial ecosystems created and maintained by human beings. Examples are aquarium, garden, agriculture, apiary, poultry, piggery, city, town, dams, etc.

  1. Natural Ecosystem

Natural ecosystems are further divided into aquatic ecosystems and terrestrial ecosystems.

  • Aquatic Ecosystem:  The ecosystem in the water body is called an aquatic ecosystem. This can be further divided into two types. 

(i) Freshwater Ecosystem: The water is sweet and has no salt. This includes lakes, ponds, rivers, streams, and wetlands.

(ii) Marine Ecosystem: The water of this ecosystem has more salt content and cannot be consumed. A variety of animal and plant life can be found here compared to the freshwater ecosystem. This includes the sea and oceans. 

  • Terrestrial Ecosystem: This ecosystem is found on land only. This comprises both biotic and abiotic components that are interrelated with each other. Examples include forest, tundra, grassland, and deserts. 
  • A forest consists of several trees, animals, and microorganisms that live in collaboration with the abiotic components of the environment. Forests are vital in maintaining the temperature, generating oxygen, and reducing carbon dioxide in the air. 
  • Grassland ecosystems are the areas dominated by grass. . They are found in tropical and temperate regions with insufficient rainfall. Savanna is one more example of a grassland ecosystem.
  • Tundra ecosystems are found in the Arctic region, on top of the mountain, where the climate is cold, and rainfall is scant. The lands are covered with snow most of the year and are treeless.
  • Deserts are regions with little rainfall and sparse  vegetation. The days are hot, and the nights are cold.

The various forms of ecosystems are explained with visual diagrams for easy understanding. Students can register on Extramarks’ website and get access to our NCERT Solutions for Class 10 Science Chapter 15.

Important Ecological Concepts:

The four essential concepts of ecology are:

  1. Food Chain

A food chain is a biological process of food or energy flow, from the producer to the consumer and eventually to an apex predator or decomposer. The plants utilize light energy from the sun for photosynthesis, synthesizing their food. The light energy is converted into chemical energy and eventually passed through successive trophic levels.

Decomposers like bacteria and fungi break down the complex organic compounds of dead plants, animals, and organic debris into simple inorganic substances, releasing chemicals like phosphorus, nitrogen, and calcium into the soil. Plants(producers) utilise these chemicals to make nutrients. 

Examples of Food Chains: Grass(Producer, T1) →, Deer(Herbivore, T2) →, Lion(Carnivore, T3) 

  1. Food Web

The Food web is the graphical representation of various interconnected food chains of different trophic levels in the ecosystem, where plants are the foundation of all the food chains throughout the food web.

  1. Trophic level pyramid

Also called an ecological pyramid is a graphical representation of the number, energy, and biomass of each trophic level in a given ecosystem. 

There are usually four trophic levels:

  • I trophic level: It consists of producers or autotrophs, for example, phytoplankton, grass, trees, etc.
  • II trophic levels: It includes primary consumers or herbivores, for example, zooplanktons, grasshoppers, cows, insects, etc.
  • III trophic levels: It includes secondary consumers or small carnivores, for example, frogs, mice, birds, fishes, etc.
  • IV trophic levels: It includes tertiary consumers or larger carnivores, for example, humans, lions, tigers, etc.
  1. Energy flow:

It is the transfer of energy from one trophic level to another. The pyramid of energy depicts the direction and amount of energy transferred. The 10% rule states that only 10% of energy is transferred from one trophic level to another in any food chain.

Students can refer to NCERT Solutions for Class 10 Science Chapter 15 for in-depth information and explanation about the four essential concepts of ecology.

Environmental Problems: 

In the present world, some harmful human activities affect the environment in many ways—for example, Air pollution, Depletion of the Ozone Layer, and Waste disposal.

  1. Air Pollution

It is caused due to many pollutants, organic molecules, or other hazardous substances in the atmosphere.

  1. Depletion of Ozone Layer

The ozone layer protects living beings from harmful ultraviolet rays from the sun. The absence of this layer can cause many health conditions like skin cancer and the destruction of plants and weaken the immune system. When excessive CFCs (Chloro Fluoro Carbon) are released into the air, they react with ozone molecules and deplete the ozone layer.

  1. Waste or garbage disposal

Industrialization and modern lifestyle have resulted in tremendous waste generation. For example, Plastic bags, disposals, etc., which are non-biodegradable, cause harm to nature in the long run.

Managing the Garbage that we Produce: 

Proper waste management should be followed right from its inception to its final disposal. The following steps can be used to manage waste and proper monitoring and regulation.

  1. Segregation of waste.
  2. Collection.
  3. Transport.
  4. Treatment.
  5. Processing & Recycling.
  6. Disposal.
  7. Less usage of non-biodegradable items like plastics, styrofoam, and thermocouples.

Environmental pollution is a growing concern and students should be sensitized to the same. Waste management processes are elaborated further in our NCERT Solutions for Class 10 Science Chapter 15. 

NCERT Solutions for Class 10 Science Chapter 15: Exercises &  Solutions

One of the best ways to prepare for the examination is by referring to and practicing the questions given in our NCERT Solutions for Class 10 Science Chapter 15. All the questions are backed with answers to help them understand the important points easily and make them revise quickly. . Questions from the textbooks are also available for further practice. Solutions have been curated to bring conceptual clarity among the students and enhance their knowledge with concise answers that can help them in their higher studies as well. 

Students may study various questions, such as MCQs, short and long-answer questions, and more. The questions and their solutions are consolidated and carefully curated under the links given below: 

  • NCERT Solutions-Very Short-answer Questions
  • NCERT Solutions – Short-answer Questions
  • NCERT Solutions – MCQ’s
  • NCERT Solutions – Long-answer Questions

Along with Class 10 Science solutions, you can explore NCERT Solutions on our Extramarks’ website for all primary and secondary classes.

Chapter 1 Chemical Reactions and Equations
Chapter 2 Acids, Bases and Salts
Chapter 3 Metals and Non-metals
Chapter 4 Carbon and Its Compounds
Chapter 5 Periodic Classification of Elements
Chapter 6 Life Processes
Chapter 7 Control and Coordination
Chapter 8 How do Organisms Reproduce?
Chapter 9 Heredity and Evolution
Chapter 10 Light Reflection and Refraction
Chapter 11 Human Eye and Colourful World
Chapter 12 Electricity
Chapter 13 Magnetic Effects of Electric Current
Chapter 14 Sources of Energy
Chapter 15 Our Environment
Chapter 16

NCERT Exemplar Class 10 Science 

NCERT Exemplar Class 10 Science Chapter 15 is one of the most definitive study and practice materials. Students need to explore a repository of questions to practice and score good grades. . By practicing these advanced Exemplar questions thoroughly along with the NCERT Solutions for Class 10 Science Chapter 15, students strengthen their concepts, analyze their shortcomings, and overcome them ahead of the board examinations. It also helps students in improving their time management skills.

Students can refer to the Exemplar problem and Solutions for Class 10 Science from the below link:

  • NCERT Solutions Class 10 Science -Exemplar

Key Features of NCERT Solutions for Class 10 Science Chapter 15

The benefits of NCERT Solutions for Class 10 Science Chapter 15 include:

  • Our NCERT solutions are structured in lucid and simple language that is easy to understand.
  • NCERT Solutions provide detailed answers to the chapter questions, and advanced tricky questions along with exercises to help students be confident in the subject and perform exceedingly well in the exams.
  • The notes are prepared by highly qualified and experienced faculty who meticulously follow the latest NCERT textbooks to provide authentic and reliable study material to students.  .
  •  NCERT Solutions for Class 10 Science Chapter 15 provides well-explained solutions to all the in-text and end-text questions in the chapter. 
  • Our study materials help students become confident in the concepts they have learned and prepare well for examinations
  • NCERT Solutions on Extramarks can be referred for CBSE Examinations and competitive examinations such as Olympiads, JEE, NEET, etc.
  • The content provided by the Extramarks is regularly updated as per the CBSE Board.

Q.1 Which of the following groups contain only biodegradable items?

1. Grass flower and leather
2. Grass, wood and plastic
3. Fruit-peels, cake and lime juice
4. Cake, wood and grass


c) Fruit-peels, cake and lime juice and d)cake, wood and grass

Q.2 Which of the following constitute a food chain?

1. Grass, wheat and mango
2. Grass, goat and human
3. Goat, cow and elephant
4. Grass, fish and goat


b) Grass, goat and human

Q.3 Which of the following are environment friendly practices?

1. Carrying cloth bags to put purchases in while shopping
2. Switching off unnecessary lights and fans
3. Walking to school instead of getting your mother to drop you on her scooter
4. All of the above


d) All of the above

Q.4 What will happen if we kill all the organism in one trophic level?


Death of all the organisms of one trophic level would affect the organisms of the previous trophic level and the next trophic level. If all the organisms of one trophic level are killed then the number of organisms of the next trophic level would decrease as they feed on the organisms of the trophic level. The number of organisms of the previous trophic level would increase because the organisms that feed on them are killed.

For example in the food chain comprising of, Grass —> Goat —> Lion, if all the goats are killed then the number of lions would decreases due to lack of food and grass population would increase due to under grazing.

Q.5 Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to ecosystem?


Yes, the impact of removing all the organisms in a trophic level will be different for different trophic levels. If the organisms of first trophic level i.e., producers are removed, then the entire food chain will be disturbed and finally all the organisms might die. If the organisms of the topmost trophic level are removed then a disturbance in the ecosystem would occur as there would arose a competition in the organisms of the second topmost trophic level for food and space due to their overproduction in the absence of the organisms of the topmost trophic level.

Removal of organisms of any trophic level would definitely create a disturbance in the ecosystem. Hence, in an ecosystem, organisms of any trophic level cannot be removed.

Q.6 What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?


Biological magnification is a phenomenon of accumulation or increase in the concentration of some toxic substance in the bodies of organisms of each trophic level.

Pesticides like DDT etc are generally sprayed on plants to eradicate pests. These pesticides are then washed down into soil and water bodies. Plants absorb these substances with water whereas aquatic animals such as fishes take up these substances from the water body. On eating these plants and aquatic animals, these toxic substances enter our body.

Yes, the magnification is different at different trophic levels of the ecosystem. The animals at the higher trophic levels will receive more of these toxic substances along with their food than animals at the lower trophic level. Thus, at each tropic level the magnification will be high as compared to the previous trophic level.

Q.7 What are the problems caused by the non-biodegradable wastes that we generate?


The waste that is not degraded in the nature is called non-biodegradable waste. The non-biodegradable wastes cause the following problems:

1. They increase soil and water pollution.
2. Non-biodegradable waste like polyethene bags blocks the drains.
3. Disposal of these non-biodegradable waste releases poisonous gases that pollute the air also.

Q.8 If all the waste we generate is biodegradable, will this have no impact on the environment?


Though the biodegradable waste do not stay for long in the environment but their excess pose various threats to the environment. Accumulated biodegradable waste like kitchen waste serves as a breeding ground for various flies, mosquitoes, microorganisms etc that may cause various diseases and epidemics in their surroundings.

Q.9 Why is damage to ozone layer a cause for concern? What steps are being taken to limit this damage?


Hole in ozone layer will allow ultraviolet rays to reach the earth’s surface. These ultraviolet (UV) rays are harmful for living organisms in the following ways:

1. These rays may cause skin disease, such as skin cancer.
2. These rays cause retarded growth and destruction of pigments in plants.
3. UV rays may disturb the ecological balance by killing the microorganisms, decomposers and other useful microbes

Following steps should be taken to prevent damage of ozone layer:

1. According to Montreal Protocol (1989) the compounds like chlorofluorocarbons which cause depletion or hole in ozone layer should be used judiciously
2. Use of chemical pesticides should be minimised
3. Use of public transport should be encouraged

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