Class 10 Science Chapter 15 Our Environment

‘Environment’ is not a strange word to us, we hear it all the time. We know what is environment, as we have been studying about it from earlier classes. In class 10 science chapter 15 our environment, we will learn how different components present in the environment interact with each other and how we humans are affecting the environment.

So far in class 10th science, we have dealt with so many difficult chapters, compared to them this chapter looks very easy, and students often make the mistake of taking this lesson for granted. Don’t underestimate this chapter as it may affect your overall total.

Class 10 Science Chapter 15 Our Environment

Not only from an exam point of view, the class 10 science chapter 15 our environment is important for practical life also. One must be aware of the environment and how our activities can affect the environment. Students need to understand this chapter now than ever.

# 15.1 — Eco-system — what are its components

First, let’s understand what is eco-system. all living beings, as well as the physical surroundings, interact with each other in order to maintain balance in nature. All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem.

So, we can say that an ecosystem has both biotic and abiotic components such as temperature, rainfall, wind, etc.

15.1.1 — Food chains and webs

The series of organisms feeding on one another and taking part at various biotic levels form a food chain. The flow of the food chain is as follows: sunlight → producers → herbivores → carnivores → top carnivores. This part of class 10 science chapter 15 our environment teaches us the following points:

•  As energy moves progressively through the various trophic levels, it is no longer available to the previous level.
• As the energy is lost at each trophic level, therefore, the energy available at each trophic level gets diminished progressively.
• Since human beings are at the top level in all food chains, therefore, the maximum concentration of the harmful chemicals that enters the food chain gets accumulated in our bodies. This phenomenon is also known as biological magnification.

Class 10 Science Chapter 15 Our Environment

Every day we come across so many environmental problems. There is not a single day when we do not read about the degrading environmental conditions in newspapers and news channels. Class 10 science chapter 15 our environment informs students about their daily activities that are in one way or the other causing harm to the environment.

# 15.2 — How do our activities affect the environment?

We already know that we humans cause air pollution in the environment, but this is not the only way we are affecting our environment. In this section of class 10 science chapter 15 our environment, we will look at two more problems that we have created i.e depletion of the ozone layer and waste disposal.

15.2.1 — Ozone layer and how it is getting depleted

Three atoms of oxygen form a molecule called ozone (O3). We know that O2 or oxygen is necessary for all organisms, but O3 is exactly the opposite, it is a deadly poison. But, at the higher level of the atmosphere, it acts as a shield and prevents the harmful ultraviolet (UV) rations coming from the sun. These rations are very dangerous for organisms.

UV radiations when acts on oxygen (O2) molecules at a higher level, ozone is formed. The UV radiation split apart some molecular oxygen into free oxygen atoms. These atoms then combine with the molecular oxygen to form ozone.

In the 1980s, the level of ozone in the atmosphere began to drop sharply. It was due to synthetic chemicals such as chlorofluorocarbons (CFCs). The CFCs were used in refrigerants and other things like fire extinguishers.

In 1987, the United Nations Environment Programme (UNEP) proposed an agreement according to which all the CFC production at 1986 levels were to be freezed, to which all nations agreed. It is now mandatory for all manufacturing companies to make CFC-free refrigerators throughout the world.

Class 10 Science Chapter 15 Our Environment

Waste disposal is one of the major challenges that we are facing in our effort to improve the environment. Our population is rising day by day. And logically, more the pollutions more will be the waste and hence more environmental issues. In this part of class 10 science chapter 15 our environment, we will look at the problems caused due to inefficient waste management.

15.2.2 — Managing the garbage we produce

Biodegradable substances: All those substances that can be broken down by biological process and hence decompose are called biodegradable substances.

Non-biodegradable substances: The substance that can not be broken down by biological processes and hence does not decompose are called biodegradable substances. These substances persist in our environment for a long time and even harm various organisms in the food chain.

With advancements in technology, we humans have found different ways to make our lives more comforting and easy. But, as humankind has progressed, so has the harmful effect that we are causing on the environment.

Plastic is one of the best examples of humans’ contribution to harming the environment. It is a non-biodegradable substance that does not decompose meaning anything made up of plastic will remain in the environment forever. Plastic is the main challenge in managing the garbage we produce.

Summary of Class 10 science chapter 15 our environment

• The various components of an ecosystem are interdependent.
• The producers make the energy from sunlight available to the rest of the ecosystem.
• There is a loss of energy as we go from one trophic level to the next, this limits the number of trophic levels in a food chain.
• The ozone layer protects against the ultraviolet radiation from the Sun. The use of chemicals like CFCs has endangered the ozone layer which could damage our environment.
• The waste we generate may be biodegradable or non-biodegradable.

Hope you have learned the valuable lessons of saving the environment that this chapter is meant to teach students. You are the future, and your small efforts can make a big change, so, try to remain aware and save the environment wherever you can.