Welcome to the NCERT Solutions for Class X Science Chapter 15 – Our Environment, brought to you by Swastik Classes. This chapter deals with the concept of the environment and its components, including biotic and abiotic factors, ecosystems, food chains, and energy flow. It also covers various environmental issues such as air pollution, water pollution, solid waste management, and their impact on living organisms.
Our solutions are designed to help students of Class X understand the fundamental concepts of the chapter and build a strong foundation in the subject. With step-by-step explanations and diagrams, our solutions provide an in-depth understanding of the concepts and help students in their exam preparation.
At Swastik Classes, we believe that education should be accessible to all, and that is why we offer these NCERT Solutions for free. We hope that our solutions will help students to perform well in their exams and achieve their academic goals.
Download PDF of NCERT Solutions for Class 10 Science Chapter 15 Our Environment
Answers of Science NCERT solutions for class 10 Chapter 15 Our Environment
Why are some substances biodegradable and some non-biodegradable?
Substances which can be acted upon by microorganisms (decomposers) are called biodegradable. For example- vegetable wastes, paper, cotton etc.
On the other hand, materials which are not acted upon by decomposers are called non-biodegradable. For example- plastic, glass, polyethene etc.
Give any two ways in which biodegradable substances would affect the environment.
(a) They will serve as breeding ground for flies and mosquitoes which are carriers of disease like cholera, malaria etc.
(b) They produce a foul smell, thus causing air pollution.
Give any two ways in which non-biodegradable substances would affect the environment.
(a) Excess use of non-biodegradable pesticide and fertilizers run off with rain water to water bodies causes water pollution.
(b) They may choke the sewer system of the city or town that may overflow over roads.
What are trophic levels? Give an example of a food chain and state the different trophic level in it.
The various links or steps in a food chain at which the transfer of food and energy takes place are called trophic levels
The producers form the first trophic level as they manufacture food. The primary consumers form the second trophic level, the secondary consumers form third and the tertiary consumers form the fourth trophic level
What is the role of decomposers in the ecosystem?
They decompose dead remains of plants and animals and their waste organic products into simple inorganic substances which are released into the atmosphere for reuse by the plants. Thus, they help in recycling of materials.
What is ozone and how does it affect any ecosystem?
Ozone is a form of oxygen. It has the molecular formula O3. It is present at a higher level in the atmosphere. It protects the ecosystem from the harmful effects of ultraviolet rays coming from the Sun. UV rays may cause skin cancer, cataract to human beings.
How can you help in reducing the problems of waste disposal? Give any two methods.
The following measures can be adopted for reducing the problem of waste disposal:
(i) Reduce the volume of wastes by burning in the incinerator.
(ii) Produce compost and biogas from biodegradable waste.
Which of the following groups contain only biodegradable items?
(a) Grass, flowers and leather
(b) Grass, wood and plastic
(c) Fruit peels, cake and lime juice
(d) Cake, wood and grass
(a), (c) and (d)
Plastic is not biodegradable, every other mentioned thing is biodegradable.
Which of the following constitutes a food-chain ?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
(b) Grass, goat and human.
Which of the following are environment friendly practices ?
(a) Carrying cloth-bags to put purchases in while shopping
(b) Switching off unnecessary lights and fans
(c) Walking to school instead of getting your mother to drop on her scooter
(d) All of the above
(d) All of the above.
What will happen if we kill all the organisms in one trophic level?
The food chain would end and ecological balance would be affected.
If the herbivores are killed, then the carnivores would not be able to get food and would die.
If carnivores are killed, then the population of herbivores would increase to unsustainable levels.
If producers are killed, then the nutrient cycle in that area would not be completed.
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 the ecosystem?
Yes, the impact of removing all the organisms in a trophic level will be different for different trophic levels. For example, on removing producers; herbivores would not be able to survive or they would migrate and the ecosystem would collapse. If herbivores are removed, producers would grow unchecked and carnivores would not get food. If carnivores are removed, herbivores would increase to unsustainable levels and could destroy the producers. If decomposers are removed, the dead animals would pile up due to which the environment would become polluted. In addition to this, if dead animals will not decompose, the recycling of nutrients in the soil will be stopped and its fertility will be reduced. As a result the green cover of the earth will be lost. Thus to maintain the balance of the ecosystem the presence of organisms is necessary at each trophic level.
No, we can’t remove any trophic level without causing damage to the ecosystem as they are all interdependent.
What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
Biological magnification : The increase in concentration of harmful chemical substances like pesticides in the body of living organisms at each trophic level of a food chain is called biological magnification.
Yes, levels of biomagnification would increase as the trophic level increases and would be the highest for the topmost trophic level. It would affect their biological processes such as growth, reproduction, etc.
What are the problems caused by the non-biodegradable wastes that we generate?
The problems caused by the non-biodegradable wastes are :
If the quantity of non-biodegradable matter increases in nature then biomagnification of poisonous chemicals in our body increases.
If the non-biodegradable waste keeps on increasing there will not be left any substance for new organisms.
The increasing quantity of non-biodegradable waste will cause an imbalance of the ecosystem.
If all the waste we generate is biodegradable, will this have no impact on the environment?
If all the waste we generate is biodegradable, it will also have an impact on the environment. If it is disposed off properly, the problem of air, water and soil pollution can be lessened to an extent. There would be less health problems and humans would be disease-free.
But if it is not disposed off properly, it will affect the environment adversely.
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
The damage to the ozone layer is a cause for concern because if the ozone layer in the atmosphere disappears completely, then all the extremely harmful ultraviolet radiations coming from the sun would reach the earth. These ultraviolet radiations would cause skin cancer and other ailments in humans and animals and also damage the plants.
In an attempt to protect the ozone layer, the United Nations Environment Programme (UNEP) unanimously forged an agreement among its member countries to freeze CFC production at 1986 levels.
Access Chapter wise NCERT Solutions for Class 10 Science chapter 15 Our Environment ( All In-text and Exercise Questions Solved)
In-text Questions Page: 260
Q1. What are the trophic levels? Give an example of a food chain and state the different trophic levels in it.
In the food chain, the transfer of food or energy takes place at various levels and these levels are known as trophic levels.
Grass → Goat → Man
In the food chain,
- Grass represents the first trophic level
- The goat represents the second trophic level
- Man represents the third trophic level
Q2. What is the role of decomposers in the ecosystem?
Following is the role of a decomposer in the ecosystem:
- They act as a cleansing agent of the environment by decomposing the dead plants and animals
- They help in recycling the nutrients
- They provide space for new beings in the biosphere by decomposing the dead
- They help in putting back the various elements into water, soil and air for the reuse of producers like crop plants.
In-text Questions Page: 262
Q1. Why are some substances biodegradable and some non-biodegradable?
The reason why some substances are biodegradable and some non-biodegradable is because the microorganisms like bacteria and decomposers like saprophytes have a specific role to play. They can breakdown only natural products like paper, wood, etc. but they cannot breakdown man-made products like plastics. Based on this, some substances are biodegradable and some non-biodegradable.
Q2. Give any two ways in which biodegradable substance would affect the environment.
Following are the ways in which biodegradable substances would affect the environment:
- They keep the environment clean as they are easily decomposed.
- They can easily go through the geochemical cycle with the help of decomposers.
Q3. Give any two ways in which non-biodegradable substances would affect the environment.
Following are the ways in which non-biodegradable substances would affect the environment:
- They cause air, soil and water pollution.
- They may cause bio-magnification in the food chain resulting in the end of human.
In-text Questions Page: 264
Q1. What is ozone and how does it affect the ecosystem?
Ozone is a molecule formed by the three atoms of oxygen and is known as an isotope of oxygen. The main function of ozone layer is to provide protection to the earth’s surface from the harmful UV rays of the sun. These rays are harmful to living organisms and may result in skin cancer.
Q2. How can you help in reducing the problem of waste disposal? Give any two methods.
Following are the ways to reduce the problem of waste disposal:
- 3 R’s: By following the 3 R’s one can reduce the problem of waste disposal. The 3 R’s are reduce, recycle and reuse. Reducing the usage of their own vehicles and opting for public transport can reduce air pollution. Recycling and reusing of plastics is also a way to reduce waste disposal.
- Preparation of compost: All the biodegradable waste like kitchen waste, can be dumped in the compost.
Exercise Questions Page: 264
Q1. Which of the following groups contain only biodegradable items?
a. Grass, flowers and leather
b. Grass, wood and plastic
c. Fruit peels, cake and lime juice
d. Cake, wood and grass
a) Grass, flowers and leather
c) Fruit peels, cake and lime juice
d) Cake, wood and grass
Above all are the groups that contain only biodegradable items. Since plastic is not a biodegradable substance, that group cannot be considered as a biodegradable.
Q2. Which of the following constitute a food-chain?
a. Grass, wheat and mango
b. Grass, goat and human
c. Goat, cow and elephant
d. Grass, fish and goat
b. Grass, goat and human
Here, the grass is the producer, goat is the primary consumer and human is the secondary consumer.
Q3. Which of the following are environment-friendly practices?
a. Carrying cloth bags to put purchases in while shopping
b. Switching off unnecessary lights and fans
c. Walking to school instead of getting your mother to drop you on her scooter
d. All of the above
Solution: d) All of the above
Q4. What will happen if we kill all the organisms in one trophic level?
If we kill all the organisms in one trophic level, the food supply to the next level will strop resulting in imbalance of the ecosystem. As a result animals in the higher levels will die making the growth of animals in the lower trophic level increase in an enormous way. All of this will affect the overall balance in the ecosystem.
Q5. Will the impact of removing all the organisms in the trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
Yes, the impact of removing all the organisms in a trophic level will be different for different trophic levels. For example, if all the producers are removed, there is a chance of death or migration of the primary consumers which will upset the trophic levels. This is same for all the levels. Therefore, the removal of organisms at any level would upset the whole ecosystem as the food chain is disturbed. The survival of the higher level animals is completely dependent on the animals at the lower levels.
Q6. What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
Biological magnification can be defined as the progressive increase in the concentration of non-biodegradable wastes in the food chain. As there is an increase in the magnification at the primary level of the ecosystems, all the other levels do get affected and the concentration may vary when compared to first level.
Q7. What are the problems caused by the non-biodegradable wastes that we generate?
Following are the problems caused by the non-biodegradable wastes:
- These substances cannot be decomposed by the microorganisms.
- As the quantity increases, dumping becomes a problem.
- Non-biodegradable wastes like heavy metals may enter the food chain in the upper trophic levels.
- They may escape to the groundwater which causes soil infertility and disturbance in pH of the soil.
Q8. If all the waste we generate is biodegradable, will this have no impact on the environment?
Biodegradable wastes are decomposed by the microorganisms into simpler substances which can be used by the producers as a raw material. But following are the effects of too much of biodegradable wastes:
- As the decomposition of the biodegradable wastes are slow, they produce an awful smell and when inhaled by humans it can be harmful.
- The dumping areas can be a place where harmful organisms may start to breed which can be harmful to humans as well as plants and animals.
- Increase in the number of aquatic organisms may result in depletion of oxygen.
Q9. Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
The ozone layer is a protective cover for the earth. It prevents harmful UV rays from entering the earth as these rays harmful and can result in skin cancer. But the air pollutants like chlorofluorocarbons (CFCs) are the main reason for the depletion of the ozone layer. Too much of UV rays are harmful to plants as they affect photosynthesis, destroy planktons and decomposers. These are the reasons why damage of ozone layer is a cause of concern.
Steps taken to limit this is that many developing and developed countries have signed and are obeying the directions of UNEP (United Nations Environment Programme) to freeze or limit the production and usage of CFCs.
NCERT Solutions For Class 10 Science Chapter 15 Our Environment
Chapter 15 Our Environment is one of the important chapters in Class 10 Science with a marks weightage of 3 marks. In Chapter 15 of NCERT Solutions for Class 10 Science, students will learn in detail about the ecosystem and its component along with the various human activities that affect the environment.
Topics covered in this chapter:
- Food Chains and Webs – 2 question (2 long)
- Managing the garbage that we produce – 3 questions (3 long)
NCERT Solutions For Class 10 Science Chapter 15 Our Environment
All organisms such as microorganisms, plants, animals and human beings, along with the physical surroundings interact with each other and maintain a balance in nature. All these interacting organisms, along with non-living constituents of the environment form an ecosystem. Chapter 15 of NCERT Solutions class 10 science discusses how various components in the environment interact with each other and how humans impact the environment.
Key Features of NCERT Solutions for Class 10 Science Chapter 15 Our Environment:
- Provides comprehensive answers to the chapter questions
- Lucid language is used that can be understood by all
- Genuine and appropriate answers provided
- These solutions can be referred for CBSE exams, Olympiads and other competitive exams
- Concise answers provided to help students understand better
The NCERT Solutions for Class X Science Chapter 15 – Our Environment, provided by Swastik Classes, is a comprehensive guide for students to understand the various concepts related to the environment. This chapter deals with the study of various components of the environment such as biotic and abiotic factors, ecosystems, food chains, and energy flow. It also covers important topics such as air and water pollution, solid waste management, and their impact on living organisms.
The solutions provided by Swastik Classes are designed to help students understand these concepts clearly and concisely. Our step-by-step explanations and diagrams provide students with an in-depth understanding of the subject matter, making it easier for them to prepare for their exams. We hope that our solutions will be useful to students and help them achieve their academic goals.
At Swastik Classes, we believe in making education accessible to all, and our solutions are available for free. We hope that students will take advantage of these resources to strengthen their understanding of the subject and perform well in their exams.
What are the types of questions asked from the Chapter 15 of NCERT Solutions for Class 10 Science?
The types of questions asked from the Chapter 15 of NCERT Solutions for Class 10 Science are –
1. Very short answer
2. Short answer
3. Long answer
In Chapter 15 of NCERT Solutions for Class 10 Science, 3 MCQs, 1 very short answer, 7 short answer and 5 long answer type of questions are present. Students can answer the very short answer type of questions in a single sentence.