Class 6 SS Geo Forms of Earth extra questions

Geo-forms of the Earth

Question Bank

	Very short question and Answers	(1 mark)
	1.       Name the four realms of the Earth. Ans: Lithosphere, Hydrosphere, Atmosphere and Biosphere 2.       What are landforms ? Ans : Landforms or relief features represent the surface layer of the Earth-lithosphere. 3.       What is a snow cap ? Ans: When the peak of a mountain is covered with snow it is called a ‘snowcap’ 4.       What is a glacier ? Ans: Rivers of ice flowing down from the snow caps of mountains are called glaciers. 5.       Name two glaciers. Ans: Gangotri in Himalayas and Siachen in Karakoram range. 6.       What are mountain ranges ? Ans: Mountains are generally formed in long chains covering hundreds of kilometers known as ranges. 7.       What are the types of mountains according to mode of formations. Ans: Fold Mountains, Block Mountains, Volcanic mountains, Residual mountains. 8.       Which landform is called a tableland ? Ans: Plateaus are known as tablelands. 9.       What is known as the ‘Roof of the World” ? Ans: The Tibetan Plateau 10.   Name the highest peak of the world . Ans: Mount Everest with a height of 8,850 metres is the highest peak in the world. 11.   Name the largest volcano in the solar system. Ans : Olympus Mons on the planet Mars 12.   Name a coastal plain of India . Ans: Malabar Plain. 13.   Which is the world’s largest island ? Ans : Greenland is the world’s largest island with an area of 2,175,000 sq km.	1
	Short answers	3 marks
	14.   How are volcanic mountains formed ? Ans: Volcanic Mountains are formed when hot molten lava erupts from vents on the Earth’s surface . Lava along with dust, ashes, liquid mud etc accumulates the vent in layers.  These layers eventually cool and solidify to form volcanic mountains. 15.   Explain the formation of a volcanic plateau. Ans : Sometimes molten lava erupts from the cracks on the earth surface, and solidifies on its surface in successive layers . These layers form a lava or volcanic plateau. For eg : Deccan Plateau in India 16.   Label the different parts of  a Volcanic mountain. 17.   What are Structural Plains ? Ans: Structural Plains are formed by internal forces that result in upliftment of the horizontal layers of the Earth. Eg: Central lowlands of Australia  18.    What are Residual Plateau  ? Explain with examples. Ans: Residual plateau are formed by continuous process of erosion. Natural agents such as wind, rivers, rain, etc, may erode an old fold or a block mountain into a plateau. For eg : the Fjeld Plateau in Scandinavia, the Cumberland Plateau in the USA 19.   What are Erosional Plains? Ans : Plains that are carved when rivers , wind, glaciers etc erode and smoothen the irregularities of the Earth’s surface. Eg : Interior plains of Canada. 20.   What harm has mankind caused to his home planet ? Ans : mankind inhis attempt to establish their settlements on different landforms has polluted air and water bodies, caused deforestation and degradation of land. 21.   Define the following :- a.       Peninsula                   b. Isthmus                           c. Island Peninsula: An area of land surrounded by water on three sides. An example of a peninsula is the Indian Peninsula. Isthmus: a narrow strip of land with sea on either side, forming a link between two larger areas of land. Isthmus of Panama Island: Island is a piece of land surrounded by water all sides. Eg: Greenland 22.   Explain the internal forces according to the Continental Drift Theory and the Plate Tectonic Theory. Ans : The Continental Drift Theoryand the Plate Tectonic Theory state that the crust of the Earth is divided into plates, which are in constant motion due to these internal forces. These plates collide with each other causing earthquakes and volcanoes.   23.   Explain the different types of Internal forces based on speed. Ans ; based on speed , the movement within the Earth due to internal forces are of two types- slow and fast. Slow movements : Slow movements within the Earth are either caused by compression or by tension. Internal forces also result in the formation of mountains and plateaus due to constant movements of the Earth’s plates. Fast /sudden movements: These movements cause considerable deformation over a short spans of time, and may be of two types: Earthquakes and volcanoes. 24.   What are the major and minor landforms of the earth. Ans : Geographers have divided the major landforms into mountains, plateaus and plains based on their height and slope. Likewise minor landforms can be classified into peninsula, isthmus and island. 25.   Why are the old fold mountains shorter in height than the young fold mountains ? Ans: Old fold mountains have been considered eroded by natural agents and so they are shorter in height than the young fold mountains. 26.   Differentiate between Aggradation and Degradation Aggradation Degradation 1.       Aggradation is caused due to depositional activity. 2.       The deposition of material is by a river, stream, or current. 3.       Aggradation means the increase in land elevation, typically in a river system, due to the deposition of sediment 1.       Degradation is caused due erosional activity. 2.       It is the wearing down of rock by disintegration. 3.       Degradation is the act of lowering something. 27.   Why are plains so important for human habitation ? Ans : Plains  are the most popular habitation sites for human settlements because of the following reasons:- ·         Fertile soils of plains are useful for agriculture. ·         Rivers flowing through plains provide enough water for human settlements. ·         Construction of buildings, industries and transportation is easy on the flat lands of plains. 28.   Describe the different types of Depositional plain Ans : When various agents of erosion such as wind, rivers , glaciers, etc deposit materials over the years , they form depositional plains. Depositional plains can be of three types: ·         Alluvial plains ( deposited by rivers) eg: Indo-gangetic Plain in India and Mississippi River Plain ·         Till plain (deposited by glaciers ) eh : Plains of Indiana ( N. America) and ·         Desert plain ( by deposition of winds ) eg: sahara dessert
	Answer in detail	5 marks
	29.   Describe the formation of Fold Mountains. Ans: Fold mountains are formed when large scale Earth movements cause wrinkling or folding of the Earth’s crust along the line of weakness. The land is lifted in wavelike  formation. The upfold or anticline forms the mountain and the downfold or syncline forms the valley. Eg; the Aravallis and the Urals and the Appalachians are few examples of old fold mountains formed millions of years ago. Whereas, the Himalayas (India), the Apls (Europe), the Rockies 9 North America), Andes ( South America) are examples of young fold mountains. 30.   Differentiate between the following :- Internal and External forces Internal Forces External forces 1.       Internal forces are also called Endogenic forces 2.       Internal forces act within the earth and bring changes in the earth’s crust. 3.       Internal forces may be slow movements or fast movements. 4.       Slow movements are either  caused by compression or by tension 5.       Internal forces also result in the formation of mountains and plateaus. 1.       External forces are also called Exogenic forces. 2.       External forces act slowly on the surface of the Earth. 3.       These forces modify the irregularities created by the internal forces either by degradation or aggradation. 4.       The degradation and aggradation are carried out mainly by running water, winds, glaciers and sea waves. 5.       External forces form depositional landforms. Differentiate between : 31.   Horsts and Graben Horst Graben 1.       A Horst represents a block pushed upward relative to the blocks on either side by the faulting 2.       Horsts represent the ridges between or on either side of these valleys and are also called as Block mountain. 3.       Eg: Vindhyas and Satpuras in India 4.       Vosges and Block forests in Europe 1.       Graben is a block generally long compared to its width that has been lowered relative to the blocks on either side due to the faulting. 2.       A Graben are usually represented by low-lying areas such as rifts and river valleys 3.       Narmada Valley in India that lies between the Vindhyas and Satpuras 4.       The Rhine valley in between the Vosges and Black forest. 32.   Differentiate between Continental plateau, Intermontane plateau and piedmont plateau Continental Plateau Intermontane Plateau Piedmont Plateau 1.       Upliftment of a block of land from the adjacent lowland or sea forms Continental plateau. 2.       Eg. Chhota Nagpur Plateau in India, Plateau of Sourth Africa, meseta of Spain 1.        Intermontane Plateau is surrounded by fold mountains. 2.       Eg : The Tibetan Plateau between the Tibetan Plateau and the Kunlun fold mountains, the Bolivian plateau between two ranges of the Andes and the Snake Plateau in Columbia. 1.       Piedmont plateau lies at the foot of mountains. 2.       Eg: Plateau of Patagonia in Argentine.
	33.   How are plateaus important to us ? Ans : ·         Plateaus are rich reserves of mineral resources. The Chhota Nagpur Plateau in India is rich in coal, mica, iron ore and other minerals: the African Plateau is rich in gold, diamonds. Copper , uranium etc. ·         Many plateaus serve as good cultivation land. The Deccan Plateau contains black soil used for cotton cultivation. ·         Rivers in plateau fall abruptly down the steep slopes and form waterfalls. These waterfalls are used for hydroelectric power generation. The Jog falls in India, the Niagara falls in North America are examples of such waterfalls. ·         Plateaus attract tourists for their scenic beauty and waterfalls.