# NCERT/Textbook Solutions/Class VII/Geography

These syllabus are periodically reviewed and revised. The NCERT book for a particular subject is divided into various chapters and every chapter has a set of questions following the chapter. This section provides answers to the questions at the end of each chapter in the Geography book, Our Environment, for Class-VII.

## Chapter 01

The Questions with Answers of this chapter are provided below:-
Question 01: Answer the following questions:-
(i) What is an ecosystem?
Answer:Ecosystem is a community of living organisms in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system.
(ii) What do you mean by natural environment?
Answer: The environment which is created by nature comprises of land, water, air, plants and animals. This is known as natural environment
(iii) Which are the major components of the environment?
Answer: Two major components of the environment are- 1.natural components-land,water,plant,etc 2.Artifical/man made components - road, building, machine,etc.
(iv) Give four examples of human made environment.
Answer: Few examples of human made environment are:
* Parks
* Buildings
* Roads
* Vehicles
* Bridges
* Industries
* monuments
(v) What is lithosphere?
Answer: Lithosphere is the solid crust or the hard top layer of the earth. It includes the crust and the uppermost mantle, which constitute the hard and rigid outer layer of the Earth.
(vi) Which are the two major components of biotic environment?
Answer: Two major components of biotic environment are Plants and Animals.
(vii) What is biosphere?
Answer: Biosphere is a narrow zone of the earth where land, water and air interact with each other to support life. It consists of plant and animal kingdom together. It is a global sum of all ecosystems.
Question 2. Choose the correct answer.
(i) Which is not a natural ecosystem?
Answer: (b) Aquarium
(ii) Which is not a component of human environment?
Answer: (a) Land
(iii) Which is a human made environment?
Answer: (c) Road
(iv) Which is a threat to environment?
Answer: (b) Growing population
Question 3. Match the following.
| Col-1 | Col-2 |
| Biosphere | blanket of air which surrounds the earth |
| Atmosphere | domain of water |
| Hydrosphere | gravitational force of the earth |
| Environment | our surroundings |
| ----- | narrow zone where land water and air interact |
| ----- | relation between the organisms and their surroundings |
Answer:
| Col-1 | Col-2 |
| Biosphere | narrow zone where land water and air interact |
| Atmosphere | blanket of air which surrounds the earth |
| Hydrosphere | domain of water |
| Environment | our surroundings |
Question 4. Give reasons.
(i) Man modifies his environment
(ii) Plants and animals depend on each other
Answer:
(i) Man modifies his environment because of his growing needs. He is capable of modifying it according to his need to live a comfortable life. Humans learn new ways to use and change environment and as a result invented many things. Industrial revolution enabled large scale production of goods. Transportation became faster and more comfortable. Information revolution made communication easier and faster across the world.
(ii) Plants and animals depend on each other for their sustainability. Animals consume plants for their living and also takes oxygen from them. Few carnivorous animals inturn eat other animals. Plants are dependent on animals as they give out carbon dioxide which is important for photosynthesis. Also, dead remains of animals provide nutrients to the plants.

## Chapter 02

The Questions with Answers of this chapter are provided below:-
Question 1. Answer the following questions.
(i) What are the three layers of the earth?
Answer The three layers of the Earth are the crust, the mantle and the core.
(ii) What is a rock?
Answer Any natural mass of solid mineral matter that makes up the Earth’s crust is called a rock.
(iii) Name three types of rocks.
Answer The three types of rocks are igneous rocks, sedimentary rocks and metamorphic rocks.
(iv) How are extrusive and intrusive rocks formed?
Answer Extrusive rocks are formed by the molten lava which comes on the earth’s surface and rapidly cools down to becomes solid. When the molten magma cools down deep inside the earth’s crust then the solid rocks so formed are called intrusive rocks. and also is most power full rock
(v) What do you mean by a rock cycle?
Answer When one type of rock changes to another type under certain conditions in a cyclic manner then this process of transformation of the rock from one to another is known as the rock cycle.
(vi) What are the uses of rocks?
Answer The uses of the rocks are as follows :
* Hard rocks are used in construction of buildings and roads.
* Some rocks are shiny and precious therefore used for making jewellery.
* Rocks are made up of different minerals and are very important to humankind.
* Some are used as fuels. For example, coal, natural gas and petroleum.
* Soft rocks are used for making talcum powder, chalks etc.
(vii) What are metamorphic rocks?
Answer The rocks which are formed due to conversion of igneous and sedimentary rocks under great heat and pressure is called metamorphic rocks.
Question 2. Tick the correct answer. (i) The rock which is made up of molten magma is
Answer (a) Igneous
(ii) The innermost layer of the earth is
Answer (b) Core
(iii) Gold, petroleum and coal are examples of
Answer (b) Minerals
(iv) Rocks which contain fossils are
Answer (a) Sedimentary rocks
(v) The thinnest layer of the earth is
Answer (a) Crust
Question 3. Match the following.
| Col-1 | Col-2 |
| Core | Earth’s surface |
| Minerals | Used for roads and buildings |
| Rocks | Made of silicon and alumina |
| Clay | Has definite chemical composition |
| Sial | Innermost layer |
| ----- | Changes into slate |
| ----- | Process of transformation of the rock |
Answer
(i) Cores
(e) Innermost layers
(ii) Minerals (d) Has definite chemical composition
(iii) Rocks (b) Used for roads and buildings
(iv) Clay (f) Changes into slate
(v) Sial (c) Made of silicon and alumina
Question 4. Give reasons.
(i) We cannot go to the centre of the earth.
Answer We cannot go to the centre of the earth because the it has very high temperature and pressure and lies 6000 km below the ocean floor. We will not able to survive there because there is no oxygen orconditions. favourable
(ii) Sedimentary rocks are formed from sediments.
Answer Sedimentary rocks are formed from sediments because of extreme compression and hardening of the particles of sediment which are transported and deposited by wind, water etc.
(iii) Limestone is changed into marble.
Answer Limestone is changed into marble because of extreme heat and pressure as it is a sedimentary rock.

## See Also

NCERT/Textbook Solutions
NCERT/Textbook Solutions/Class VII/History
NCERT/Textbook Solutions/Class VII/Civics

## External Links

* Official website of NCERT
* NCERT textbooks available online