Our Changing Earth Question Answers: NCERT Class 7 Social Science - Our Environment (Geography)

Imagine an ideal environment where you would love to live. Draw the picture of your ideal environment.

(i) There is scanty vegetation in the deserts.
(ii) People of the Sahara desert wear heavy robes.

Observe the photographs given below. These are various features made by a river. Identify them and also tell whether they are erosional or depositional or landforms formed by both.

(i) Wet clothes take longer time to dry on a humid day?
(ii) Amount of insolation decreases from equator towards poles?

(i) Ocean water is salty.
(ii) The quality of water is deterioting.

(i) Sahara is located in which part of Africa
(a) eastern (b) northern (c) western

(ii) Sahara is what type of desert
(a) cold (b) hot (c) mild

(iii) The Ladakh desert is mainly inhabited by
(a) Christians and Muslims
(b) Buddhists and Muslims
(c) Christians and Buddhists

(iv) Deserts are characterised by
(a) scanty vegetation
(b) heavy precipitation
(c) low evaporation

(v) Hemis in the Ladakh is a famous
(a) temple (b) church (c) monastery

(vi) Egypt is famous for growing
(a) wheat (b) maize (c) cotton

(i) Today’s world is shrinking.

(i) Name the continent in which the Amazon Basin is located.
(ii) What are the crops grown by the people of the Amazon Basin.
(iii) Name the birds that you are likely to find in the rainforests of the Amazon.
(iv) What are the major cities located on the River Ganga.
(v) Where is the one-horned rhinoceros found?

(i) Which is not a natural ecosystem?
(a) Desert (b) Aquarium (c) Forest

(ii) Which is not a component of human environment?
(a) Land (b) Religion (c) Community

(iii) Which is a human made environment?
(a) Mountain (b) Sea (c) Road

(iv) Which is a threat to environment?
(a) Growing plant(b) Growing population (c) Growing crops

(i) Which of the following gases protects us from harmful sun vays?
(a) Carbon dioxide (b) Nitrogen (c) Ozone

(ii) The most important layer of the atmosphere is
(a) Troposphere (b) Thermosphere (c) Mesosphere

(iii) Which of the following layers of the atmosphere is free from clouds?
(a) Troposphere (b) Stratosphere (c) Mesosphere

(iv) As we go up the layers of the atmosphere, the pressure
(a) Increases (b) Decreases (c) Remains the same

(v) When precipitation comes down to the earth in the liquid form, it is called
(a) Cloud (b) Rain (c) Snow

(i) Glacier                                      (a) Sea shore
(ii) Meanders                                (b) Mushroom rock
(iii) Beach                                     (c) River of ice
(iv) Sand dunes                           (d) Rivers
(v) Waterfall                                 (e) Vibrations of earth
(vi) Earthquake                            (f) Sea cliff
                                                    (g) Hard bed rock
                                                    (h) Deserts

(i) Name the continent in which the Amazon Basin is located.
(ii) What are the crops grown by the people of the Amazon Basin.
(iii) Name the birds that you are likely to find in the rainforests of the Amazon.
(iv) What are the major cities located on the River Ganga.
(v) Where is the one-horned rhinoceros found?

(i) The process by which water continually changes its form and circulates between oceans, atmosphere and land
(a) Water cycle (b) Tides (c) Ocean currents

(ii) Generally the warm ocean currents originate near
(a) Poles (b) Equator (c) None of these

(iii) The rythmic rise and fall of ocean water twice in a day is called
(a) Tide (b) Ocean current (c) Wave

(i) Mosses and Lichens are found in:
(a) Desertic Vegetation
(b) Tropical evergreen forest
(c) Tundra vegetation

(ii) Thorny bushes are found in:
(a) Hot and humid tropical climate
(b) Hot and dry desertic climate
(c) Cold polar climate

(iii) In tropical evergreen forest, one of the common animals is:
(a) Monkey (b) Girraffe (c) Camel

(iv) One important variety of coniferous forest is:
(a) Rosewood (b) Pine (c) Teak
(v) Steppe grassland is found in

(a) S. Africa (b) Australia (c) Central Asia

Observe the photographs given below. These are various features made by a river. Identify them and also tell whether they are erosional or depositional or landforms formed by both.

(i) Oasis                                                          (a) Libya
(ii) Bedouins                                                   (b) monastery
(iii) Oil                                                             (c) glacier
(iv) Gangri                                                      (d) depressions with water
(v) Lamayuru                                                 (e) cold desert
                                                                       (f) Sahara 

(i) What is precipitation?
(ii) What is water cycle?
(iii) What are the factors affecting the height of the waves?
(iv) Which factors affect the movement of ocean water?
(v) What are tides and how are they caused?
(vi) What are ocean currents?

(i) What are the three layers of the earth?
(ii) What is a rock?
(iii) Name three types of rocks.
(iv) How are extrusive and intrusive rocks formed?
(v) What do you mean by a rock cycle?
(vi) What are the uses of rocks?
(vii) What are metamorphic rocks?

(i) The rainforests are depleting.
(ii) Paddy is grown in the Ganga-Brahmaputra plains.

(i) Which are the two factors on which the growth of vegetation mostly depends?
(ii) Which are the three broad categories of natural vegetation?
(iii) Name the two hardwood trees commonly found in tropical evergreen forest.
(iv) In which part of the world are tropical deciduous forest found?
(v) In which climatic conditions are citrus fruits cultivated?
(vi) Mention the uses of coniferous forest.
(vii) In which part of the world is seasonal grassland found?