Important Questions: Environment | Social Studies (SST) Class 7 (Old NCERT) PDF Download

Q1: Describe the Lithosphere.
Ans: Lithosphere is the solid crust or the hard top layer of the earth. It is made up of rocks and minerals and covered by a thin layer of soil. It is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc. Landforms are found over the continents and also on the ocean floors. The lithosphere is the domain that provides us forests, grasslands for grazing, land for agriculture, and human settlements. It is also a source of mineral wealth.

Q2: How can the environment impact living beings?
Or
What impact can the environment have on us?
Ans: All the living beings are directly associated with the environment. If the environment is good, the living beings will be healthy. If the environment is polluted, the living beings will be ill or unhealthy. In an unhealthy environment, many types of diseases can turn up in humans. These diseases may be respiratory, abdominal, eye-related, and some may be as chronic. Likewise, in the plants, many diseases also grow due to the unhealthy environment. And hence, the photosynthesis process in the plants becomes slow, which results in restricting the growth and functioning of plants.

Q3: How have human beings adapted to the environment to fulfil their needs?
Ans:  Human beings from the early times have been interacting with the environment and modifying it according to their needs. Early humans adapted themselves to the natural surroundings. They led a simple life and fulfilled their requirements from the nature around them. But their needs kept on increasing. They became varied also. To fulfil these varied needs, humans learnt to grow crops, tamed animals and began a settled life. The wheel was invented, surplus food was produced, a barter system emerged, trade started, and commerce developed. The Industrial Revolution made possible large-scale production. By and by transportation became faster. The information revolution made communication easier and faster across the world. In this way human beings adapted to the environment to fulfil their needs.

Q4: Give an account of atmosphere.
Ans:  Atmosphere is the thin layer of air that surrounds the earth. It is made up of various gases such as oxygen, nitrogen, carbon dioxide, dust particles, and water vapour. The gravitational force of the Earth holds the atmosphere around it. It protects us from harmful rays and scorching heat of the sun. The changes in atmosphere produce changes in the weather and climate.

Q5: What do you mean by the atmosphere? Describe in brief.
Ans: The atmosphere is the thin layer of air that surrounds the Earth. The gravitational force of the Earth holds the atmosphere around it. It protects us from the harmful rays and scorching heat of the sun. It consists of several gases, dust, and water vapour. The changes in the atmosphere produce changes in the weather and climate.

Q6: What do you understand about the Barter System?
Ans: It is a trade in which goods are exchanged without the use of money. In this system, the goods are exchanged with the goods, or you can say that goods are exchanged between the two needy people.

Q7: Describe the various causes which affect our environment.
Ans: Human activities on earth affect the whole environment. The causes which affect our environment can be listed as follows:

• Industries and means of transport which release smoke;
• Use of fertilizers and pesticides;
• Un-cleaned surrounding;
• Polluted water and air;
• Unsettled domestic as well as electronic garbage, etc.

Q8: Describe briefly about the environment.
Ans: Environment is our basic life support system. It provides the air we breathe, the water we drink, the food we eat and the land where we live. The place, people, things, and nature that surround any living organism is called the environment.
It is a combination of natural and human-made phenomena. While the natural environment refers to both biotic and abiotic conditions existing on earth, the human environment reveals the activities, creations, and interactions among human beings. There are three components of the environment: Natural, Human-made, and Human.

Q9: How do humans use the environment to fulfil their needs?
Ans: Human beings interact with the environment and modify it according to their needs. Early humans adapted themselves to the natural surroundings. They led a simple life and fulfilled their requirements from the nature around them. Humans learnt new ways to use and change the environment as times and need grew and became more varied.
They learnt to grow crops, domesticate animals and lead a settled life. The wheel was invented, surplus food was produced, a barter system emerged, trade started, and commerce developed. Industrial revolution enabled large-scale production. Transportation became faster. The information revolution made communication easier and faster across the world.

Q10: Give an account of various domains of the environment.
Ans:  Various domains of the environment are:

• Lithosphere: This is the solid crust or top layer of the Earth. It consists of rocks and minerals, topped with a thin layer of soil. It provides us with forests, grasslands, and land for agriculture, as well as a source of mineral wealth.
• Atmosphere: The atmosphere is the thin layer of air surrounding the Earth. Held by the Earth's gravitational force, it protects us from harmful rays and the intense heat of the sun. It is made up of various gases, dust, and water vapour.
• Hydrosphere: This domain includes all water bodies on Earth, such as rivers, lakes, seas, and oceans. It is essential for all living organisms.
• Biosphere: The biosphere, or the living world, includes all plants and animals. It is a narrow zone where land, water, and air interact to support life.

Q11: An ecosystem only includes animals and not plants or microorganisms. True/False 
Ans: False 

Q12: How do human beings modify the natural environment?     
Ans:  The needs of human beings are increasing day by day. Hence, they modify the natural environment to fulfil these needs. Sometimes they even destroy their environment
Human beings have made cars for their convenience. These cars release fumes, which pollute the air. They have established factories on land. These factories manufacture various items such as containers. This is how they modify the natural environment.

Q13: What is gravitational force?
Ans: The gravitational force holds the atmosphere around the Earth. It protects us from the harmful rays and scorching heat of the sun. It consists of several gases, dust, and water vapour.

Q14: Why was the environment quite well during the early period?
Ans: There were very limited needs of early men. There were no industries, transport, or other means which could produce harmful gases. The early man did not have the use of chemical products such as pesticides, fertilizers, etc. The quantum of garbage was very limited. All these things affect the environment, and thus in the early period our environment was quite well.

Q15: What is the hydrosphere, and why is it important?

Ans: The hydrosphere includes all the water on Earth. This means oceans, rivers, lakes, ponds, groundwater, glaciers, and even water in the air as clouds and moisture. Water keeps moving in a cycle, changing from liquid to gas (water vapor) and back to liquid or solid (ice). The hydrosphere is important because it supports life, helps in weather changes, and shapes the Earth's surface.