# NCERT Solutions for Class 10 Science Chapter 15 Our Environment

NCERT Solutions for Class 10 Science Chapter 15 Our Environment: You might have heard our elders saying that the 'environment' is not what it used to be earlier. In this chapter of class 10 science, we are going to learn about such transformations which have happened in our eco-system. Solutions of NCERT class 10 science chapter 15 our environment explains all the questions related to this chapter which further will increase our knowledge. Since CBSE class 10 is a board class and it becomes extremely important to understand each topic carefully, therefore, CBSE NCERT solutions for class 10 science chapter 15 our environment will give answers to all the topic related doubts mentioned in NCERT book. These are the list of the topics which you are going to study in NCERT class 10 science chapter 15 our environment chapter:

1. Eco-system - What are its Components?
2. How Do our Activities Affect Our Environment?

The NCERT solutions will be useful if you want to check out the solutions of other chapters too. This chapter of class 10 science will talk about the interdependency of various components of our ecosystem.

## Importance of class 10 science chapter 15 our environment in CBSE board exam:

In general, 4 types of questions are asked in CBSE class 10 science board exam:

• Very short type questions
• Short type questions
• Long type questions
• Practical based questions

All these types of questions vary from one mark to 5 marks. So, it becomes very important to study CBSE NCERT solutions of class 10 science chapter 15 our evironment as it is going to help you put these marks in your bucket easily. In 2017, 1 mark question was asked from this chapter in class 10 science board exam and recently, in 2018, 3 marks weightage has been given to this chapter. These marks can be availed easily by solving al the questions from NCERT book. If you have any problem in answering these questions or you are not getting the correct answers then don't worry, solutions of NCERT for class 10 science chapter 15 our environment is there to guide.

## NCERT solutions for class 10 science chapter 15 our environment topic 15.1 Ecosystem and what are its components:

Each step or level of the food chain is known as a trophic level. Transfer of energy in the form of food takes place from one trophic level to the next. Trophic levels can be broadly classified as Producers; Primary, Secondary and Tertiary Consumers.

An example of a food chain:

Grass $\rightarrow$ Grasshopper $\rightarrow$ Frog $\rightarrow$ Snake $\rightarrow$ Eagle

Here, Grass is a producer, Grasshopper is herbivore, Frog is first carnivore, Snake is second carnivore and Eagle at the top is third carnivore.

Decomposers break down the organic components of dead and decaying matter into simple inorganic substances. The organic matter like dead animal bodies are recycled in the ecosystem thereby cleaning the environment. And, the inorganic elements return back the minerals into the soil making the soil fertile. Thus, decomposers play a vital role in the ecosystem.

## Solutions of NCERT class 10 science chapter 15 our environment topic 15.2 How do our activities affect the environment?

Substances that can be broken down by biological processes are said to be biodegradable. In our environment, many of the substances are broken easily by decomposers. Examples: Paper, vegetable peels etc.

However, substances which cannot be broken down biologically but by physical means are known as non-biodegradable substances. Example: Plastic.

Two ways in which biodegradable substances would affect the environment are:

1. These substances on degradation can produce foul smell which affects the population living nearby. They may also become a breeding place for insects.

2. Many harmful greenhouse gases may evolve during degradation leading to global warming.

Any two ways in which non-biodegradable substances may affect the environment are:

1. The main problem caused is pollution. Non-biodegradble substances take many decades to degrade and hence remain in the environment causing pollution.

2. They may render the soil infertile and hence affect the vegetation

## CBSE NCERT solutions class 10 science chapter 15 our environment topic 15.2 How do our activities affect the environment?

Ozone ($O_3$) is a molecule formed by 3 oxygen atoms. Ozone is present in the stratosphere shielding the earth's surface from the harmful UV rays by absorbing it.

Ozone may affect the ecosystem in the following ways:

1. If this layer gets depleted, the UV rays can cause cancer in human beings and also some plants and animals.

2. The UV rays may effect the plants and destroy the vegetations.

Two methods used to reduce the problems of waste disposal are:

1. Throwing biodegradable and non-biodegradable waste into separate dustbins so that recycling can be done easily.
2. By putting the organic waste into compost pits dug in the ground and preparing compost. This compost helps in increasing the fertility of soil.
3. Practicing the 3 R's: Reduce, Reuse and Recycle.

## NCERT solutions class 10 science chapter 15 our environment exercise:

(a) Grass, flowers and leather

(b) Grass, wood and plastic

(c) Fruit-peels, cake and lime-juice

(d) Cake, wood and grass

Hence, (a), (c) and (d) groups contain only biodegradable items.

(a) Grass, wheat and mango

(b) Grass, goat and human

(c) Goat, cow and elephant

(d) Grass, fish and goat

A food chain constitute of different trophic levels.

(b) Grass $\rightarrow$ Goat $\rightarrow$ Human; constitute a food chain.

Here, grass is a producer, goat is primary consumer and human is secondary consumer.

(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

All of the above metioned practices are environment friendly. Hence (d) All of the above is the correct answer.

If all the organisms of one trophic level are killed, the food chain will become competely imbalanced. The organisms in the immediate higher trophic level will die out due to unavailability of food and the consequences will follow. Also, population of the organisms in the immediate lower trophic level will keep on increasing and this in turn will wipe out its immediate lower level due to higher demand but lower supply. Thus the whole food chain will collapse.

## 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 the ecosystem?

Yes, the impact of removing all the organisms in a trophic level will be different for different trophic levels.

No, the organisms of any trophic level cannot be removed without causing any damage to the ecosystem.

Consider the following example:

Grass $\rightarrow$Deer $\rightarrow$ Lion

1. If all the grass is removed, the deer will die out due to starvation which in turn will wipe out the lions.

2. If all the deer population is removed, the lions will die out due to starvation. The grasses will increase in number and turn the land into forests.

3. If all the lions are removed, the population of deer will keep on increasing which in turn will eat all the grass leaving the land barren.

Biological Magnification is the increase in concentration of harmful substances in the body of the living organism at each trophic level.

Yes, the levels of this magnification is different at different levels of the ecosystem. It is highest at the topmost level of the food chain.

As the chemicals like pesticides, DDT are non-degradable, these get accumulated progressively at each trophic level. As human beings occupy the top level in any food chain, the maximum concentration of these chemicals get accumulated in their bodies.

The non-biodegradable waste that we generate has the following problems on environment:

1. Non biodegradable wastes like pesticides reduce the fertility of soil as they penetrate into it. The pH level of the soil becomes unsuitable for vegetation.

2. Non biodegradable wastes like pesticides get accumulated progressively at each trophic level and thus harm the organisms.

3. Non-biodegradable materials like plastics on burning releases toxic chemicals into the environment which leads to air pollution.

If all the waste we generate is biodegradable, this will also have impact on the environment. These waste when not disposed properly releases foul smell which affects the population living nearby. These waste can also become breeding place for mosquitoes and other insects causing spread of diseases. Therefore, proper dumping ground should be made for these biodegradable waste.

The ozone layer in the stratosphere absorbs the harmful UV rays and thus protect the living beings. If this ozone layer gets depleted, the UV rays may cause cancer in humans and other plants and animals. Thus, damage to the ozone layer is a cause for concern.

In order to limit this damage, the production of CFC's (Cholorofluoro carbons) were stopped in 1986.

## Solutions of NCERT for Class 10 Science - Chapter wise

 Chapter No. Chapter Name Chapter 1 CBSE NCERT solutions for class 10 science chapter 1 Chemical Reactions and Equations Chapter 2 Solutions of NCERT for class 10 science chapter 2 Acids, Bases, and Salts Chapter 3 CBSE NCERT solutions for class 10 science chapter 3 Metals and Non-metals Chapter 4 CBSE NCERT solutions for class 10 science chapter 4 Carbon and Its Compounds Chapter 5 Solutions of NCERT for class 10 science chapter 5 Periodic Classification of Elements Chapter 6 CBSE NCERT solutions for class 10 science chapter 6 Life Processes Chapter 7 CBSE NCERT solutions for class 10 science chapter 7 Control and Coordination Chapter 8 Solutions of NCERT for class 10 science chapter 8 How do Organisms Reproduce? Chapter 9 CBSE NCERT solutions for class 10 science chapter 9 Heredity and Evolution Chapter 10 CBSE NCERT solutions for class 10 science chapter 10 Light Reflection and Refraction Chapter 11 Solutions of NCERT for class 10 science chapter 11 The Human Eye and The Colorful World Chapter 12 CBSE NCERT solutions for class 10 science chapter 12 Electricity Chapter 13 CBSE NCERT solutions for class 10 science chapter 13 Magnetic Effects of Electric Current Chapter 14 Solutions of NCERT for class 10 science chapter 14 Sources of Energy Chapter 15 NCERT Solutions for class 10 science chapter 15 Our Environment Chapter 16 CBSE NCERT solutions for class 10 science chapter 16 Sustainable Management of Natural Resources

## How are CBSE NCERT solutions for class 10 science chapter 15 our environment going to help you :

• In order to crack board exams, NCERT solutions for class 10 science chapter 15 our environment will be a big help as it gives detailed answers to the questions given in NCERT book.
• After you have gone through each question, it is time to practice CBSE board previous year question papers in order to get the clarity on the types of questions asked. NCERT solutions for class 10 science chapter 15 our environment will give clarity on each concept so that you are able to solve these previous year questions.
• If you need help in solving any of the questions, even outside NCERT textbook, you can contact our experts who will immediately resolve your queries.

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