NCERT Solutions for Class 10 Science Chapter 15
NCERT Solutions for Class 10 Science Chapter 15 - Our Environment
What Is Environment?
Look around you. Everything you see around you makes up the environment. Living things like animals, plants, insects and non living things like air, water, land, earth, oxygen, nitrogen, carbon dioxide, ozone etc make up the environment. Human beings are affected by the environment - both positively and negatively.
What Is an Ecosystem?
You might think that human beings are living an independent life. However, we are dependent on external environmental factors. Again, the environmental factors that human beings depend on, in turn, are dependent on other environmental factors. For example - We depend on goats for meat to stay alive and goats eat plants to stay alive.
So formally speaking, the relationships that living organisms in an area have between them and other non living things (air, water, sun light) is known as ecosystem.
What Is Food Chain?
Plants use sunlight for photosynthesis. This process of photosynthesis involves breaking down of water and CO2 to produce carbohydrates (energy) and nutrients. Plants, in turn, are eaten by deer. Deer are eaten by tigers. When the tiger dies, bacterial activities result in the decomposition of the dead body of the tiger. The decomposed body ultimately mixes with the soil and acts as the nutrients of the plants. This chain wise transfer of energy across the ecosystem is known as the food chain.
This Food Chain can be categorised into three categories -
Producers or Autotrophs - Autotrophs are those who can sustain without depending on other living things. Plants are autotrophs - they use sunlight to start photosynthesis that results in the production of nutrients. Apart from plants, algae, phytoplanktons etc are autotrophs.
Consumers - Consumers depend on producers for food. They eat producers sustain themselves. Deer eat plants to survive - they cannot produce their own food. Animals that eat plants to survive are called primary consumers. Animals that eat plant-eating animals are called secondary consumers.
Decomposers - Decomposers are the show stoppers. They complete the food chain. They break down the dead animals, decaying plants into soils that are rich in minerals.
Due to mindless activities of human beings, our environment is getting mixed with harmful solid, liquid and gases. This mixing of harmful substances in the environment that are affecting humans, plants and animals is called environmental pollution.
Land Pollution - When the earth’s surface and the soil get degraded or degenerated by the activities of human beings, we call it land pollution. There are many different causes of land pollution. The first cause that comes to mind is deforestation. Due to the increasing population, human beings need more amount of land to live on. As a result, they have to cut trees to make way for this increasing number of population. This in turn, results in soil erosion.
Again, agricultural activities can strip the land of all its positive characteristics. Overuse of pesticides, chemical fertilizers etc are harming the soil by introducing harmful chemicals and thereby increasing the chance of chemical contamination.
Garbage, both household and industrial, is another cause of and pollution. This garbage includes elements like plastics, residual chemicals from the factories etc. These days, Nuclear wastes and E-wastes are also polluting the land significantly.
Effects of Land Pollution
The results of land pollution are too dangerous to ignore. With too much agricultural activities, particularly with chemicals, the soil is losing its fertility. As a result, forests are dwindling and we have to search for more fertile lands.
Excessive use of harmful pesticides and too much garbage from the industries can contaminate the land with poisonous chemicals. These chemicals can enter our body through fruits and vegetables.
Loss of trees can result in low rainfall. And with low rainfall comes the problem of global warming, deforestation, low production of crops and what not. Loss of trees can also result in the land being eaten up by the oceans.
Deforestation due to land pollution is also harming animals in a big way. Many animals have lost their natural habitats due to deforestation. Many a times, you hear about tiger roaming around human dwellings resulting in the unfortunate killing of the tigers by people for self defence. The reason is mainly the reduction in forest cover.
When the water becomes poisonous or harmful to the living beings due to the contamination of a variety of dangerous, life-threatening and disease creating elements, we call that water pollution. Industries mindlessly drain their untreated liquid wastes into the water bodies like rivers or oceans. These liquid wastes include lead, mercury, sulphur etc that are not only harmful to animals and organisms that live in and around these water bodies, but they are also harmful to human beings. Wastes that come out of households clog the drains of the sewers in the city. These sewers are a great breeding ground for harmful bacteria.
Fertilizers and pesticides also can also come in contact with water bodies thereby contaminating it. Construction works, landfills, burning of coal and wood etc also pose a serious threat to the health of water bodies. Too much drawing up of groundwater also results in arsenic contamination.
Effects of Water Pollution
Water borne diseases are one of the most significant causes of human death. Water contamination leads to diarrhoea, cholera, typhoid in humans. Arsenic also spreads through contaminated water. Even life threatening illnesses like cancer can be a result of water contamination.
Water pollution causes significant damage to aquatic animals. This, in turn, can damage the food chain.
Harmful solid particles and poisonous gases mix in the air and cause air pollution. Whatever causes the health of the natural environment to deteriorate are known as pollutants. Harmful substances which mix with the atmosphere are air pollutants and these poisonous elements are the main reasons behind air pollution. In recent years air pollution has increased rapidly and the time has come when this menace of air pollution should be handled deftly.
The causes of air pollution are both human and natural but the human reasons far outweigh the natural reasons. Forest fires, volcanic eruptions, wind erosion, pollen dispersal, evaporation of organic compounds and natural radioactivity are natural phenomenon and they cause the air to pollute naturally. But these things do not happen on a regular basis although when they happen, they happen on a much bigger scale. But still the human activities are far more consistent and need to be remedied soon.
The urban areas are densely populated and air pollution is heavy in such areas. Car emissions, chemicals and gases from factories and dust are heavily polluting the atmosphere. Suspended particulate matter (SPM) is finely divided solids or liquids that may be dispersed through the air from combustion processes, industrial activities or natural sources.
The smoke in the industrial areas mixes with the fog and dust in winter and causes smog which is very dangerous for living beings. Again the CFC (chloro fluoro carbon ) emitted by refrigerators that are used widely in almost every household nowadays is one of the most harmful elements to be found in the air. Carbon dioxide (CO2) is a gas that living beings exhale and so it mixes with the air naturally. But things become difficult when trees are felled indiscriminately and buildings and vehicles increase in direct proportion to population explosion. Thus carbon monoxide ( CO ), sulphur dioxides ( SO2 ), carbon dioxide (CO2 ), nitrogen dioxide ( NO2 ) etc heavily mix with the air and cause air pollution. Burning of fossil fuels like coal, oil and natural gas in cities and villages alike increases the amount of pollutants in the air. In recent times, the burning of stubble in Rajasthan, Punjab Haryana has become a major issue and the main reason behind the frightening levels of air pollution in Delhi.
In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone (O3) at ground level is a harmful air pollutant.
The quality of breathable air is continuously deteriorating and if something is not done soon about this, mankind will surely be the next in the list of extinct species.
Effects of Air Pollution
The increase of harmful gases like Nitrogen Dioxide, Sulphur Dioxide, Ozone can cause irritation to our airways. A person who is already suffering from respiratory problems will be severely affected by these gases. Even the suspended particles in the air can enter the lungs and can cause serious heart and lung diseases. Any place that is polluted by Carbon Monoxide is harmful to human beings. Carbon Monoxide can lead to decrease in OXygen in the blood.
More and more children are falling prey to asthma due to air pollution. Prolonged exposure to polluted air can even lead to fatal diseases like heart problems and cancer. Air pollution is also one of the main reasons behind global warming. And due to the melting glaciers, the earth is becoming hotter day by day and animals and humans are losing their habitats because of increase in the sea level. Even the Ozone layer is quickly depleting because of air pollution.
What Is Ozone?
Ozone is made up of three atoms of Oxygen. We see Ozone as a saviour. However, Ozone is actually quite dangerous to human beings if it reaches ground level. However, this Ozone acts as a shield against the harmful UV rays from the sun. Without Ozone layer, UV rays from the sun will directly reach us. This can cause fatal diseases like skin cancer.
However, this helpful gas has been depleting since 1980s because of human activities. Mainly CFCs were responsible for this depletion. However, countries that participate in the UN, universally accepted to stop the use of CFCs (Montreal Protocol). But sadly, due to factors like global warming, the Ozone layer has not reached back to its earlier state.
How Can Vedantu Help You?
What You Will Learn In Our NCERT Solutions
In our ‘Our Environment Class 10 NCERT Solutions’ you will learn about many things related to the environment, food chain, pollution and how to create a better environment. Our Environment Class 10 extra questions are there too, to help you understand about each of the aspects of the chapter. These are the things that you will learn -
All about biodegradation - Some substances can be decomposed by bacteria and some takes a long time to be decomposed. Again there are some substances that are virtually impossible to be decomposed. You will learn about substances which can be decomposed and which cannot be. You will also learn about the harmful effects of the non-biodegradable substances.
You will learn about food chain. There is a term called trophic level. Trophic level indicates if the organism is food producer, producer eater or secondary eater. For example, grass is a producer and thus falls on Trophic Level 1, deer eats grass and therefore falls on Trophic level 2. Lion eats deer and falls under Trophic level 3.
You will learn about the role of decomposers, how they benefit the environment and keep it healthy. The main purpose of these decomposers is to complete the food chain. They break down the dead bodies of organisms into nutrient-rich soil.
You will also learn about Ozone, its benefits. You also learn about Ozone layer depletion and how to reverse it.
You will learn about how disruption of food chain can lead to the deterioration of the ecosystem.
Vedantu’s Our Environment Class 10 questions and answers PDF contains all the aspects of the chapter. From biodegradation to Ozone Layer - our solutions discuss about every part of the chapter. These solutions are exhaustive and you won’t need any other help book to learn about the chapter. There will not be anything from the chapter that will remain unlearnt if you follow our solutions.
Our Class 10 science Chapter 15 NCERT Solutions are prepared in such a way that it follows the NCERT guidelines. Our solutions focus on building the fundamental knowledge of the students on environment. That is why we have given a detailed explanation on the structure of Ozone before discussing about its helpfulness. Rest assured, your basic knowledge in environment and the things that affect it.
Our NCERT solutions for Class 10 science Chapter 15 are short and to the point. We have not prolonged our answers unnecessarily. Our answers address only the point asked in the question. That is why when answering the question on the responsibilities of decomposers, we just mentioned what the decomposers without unnecessarily defining decomposers. Again, while answering Question 1 of Ex 3, we discussed about Ozone before writing about its helpfulness because we are asked in the question toi do so. This tendency of answering only that is asked impresses the examiners. Our Chapter 15 science Class 10 solutions are thus a great way to fare well in exams.
We have ensured that our answers rekindle the lost love for the chapters that discuss about the environment. This chapter is particularly relevant in today’s context. Vedantu knows the importance of this chapter and hence we have written the answers not only keeping in mind the academic life of the students but we also kept in mind the broader picture.
Vedantu’s Our Environment Class 10 Solutions PDF is neatly arranged. The organised way of writing the answers will help the students to maintain their focus on the chapter. We have used bullets and numbering and bold headings wherever we thought necessary. That is why in answers for question 7 and 9 we used numbering. This visually pleasant way of writing answers will help students to memorise these answers easily and at the same time it will impress the examiners. Vedantu’s Ch 15 science Class 10 PDF are prepared by expert teachers who know how to write answers so that they appear pleasing to both students and the examiners. Our teachers make it sure that no point is excluded from these answers. You can use these answers with confidence in your exams. The answers are accurate and adhere to the NCERT regulations.
We have not used difficult to understand words in our solutions. But don't think that our answers are devoid of scientific terms. We have used scientific terms wherever we deemed necessary. But we avoided heavy words so that students can memorise our answers quickly. This simple yet informative way of writing answers is sure to impress the examiners. Examiners always prefer simplicity.
Vedantu’s solutions are written keeping the text book in mind. Apart from the questions that needed creativity, we followed the information given in the textbook to answer them. The answers are written as per the syllabus. Since, these answers are written keeping in mind the information discussed in the book, they can help you understand the deeper aspects of the chapter. Our answers are written in an explanatory manner. Even a cursory reading of these answers will help the students understand what is being told in them. Our answers are not meant for dry mugging. If you read our answers, your concepts about the chapter will be solidified.
We have analysed the points discussed in the chapter, so these solutions are not superficial. The answers are enriched with analytical explanations. As an example, you can look at the answer to the question - How disruption of trophic levels can lead to chaos in the ecosystem. These analytical answers will help you secure good marks in exams. Our main focus is to help students understand each of the chapters of each of the subjects without much fuss. Vedantu is motivated by the success of the students. We want the Indian students to get a quality education so that they can compete at the global level. That is why we are giving away the PDF of Our Environment Class 10 NCERT Solutions for free. You don't have to pay a single penny. Just enter your email and we will send you the download link to your email.
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