7th Std Social Science Term 3 Solution | Lesson.4. Exploring Continents – North America and South America

Lesson.4 Exploring Continents – North America and South America

7th Std Social Science Term 3 Solution in English

Lesson.4 Exploring Continents – North America and South America

I. Choose the correct answer

1. The ————– separates North America from Asia

  1. Bering Strait
  2. Palk Strait
  3. Malacca Strait
  4. Gibraltar straits

Ans : Bering Strait

2. ————– is known as the “sugar bowl of the world”

  1. Mexico
  2. USA
  3. Canada
  4. Cuba

Ans : Cuba

3. —————– are the longest rivers in North America

  1. The Mississippi and Missouri rivers
  2. The Mackenzieriver
  3. The St. Lawrence river
  4. The Colorado river

Ans : The Mississippi and Missouri rivers

4. ————– is the longest mountain chain in the world.

  1. The Andes
  2. The Rockies
  3. The Himalayas
  4. The Alps

Ans : The Andes

5. —————- basin gets rainfall every day because of its equatorial location

  1. The Mackenzie
  2. The Orinoco
  3. The Amazon
  4. The Parana

Ans : The Amazon

II. Fill in the Blanks.

1. ————–86m below the sea level is the lowest part of the continent of North America.

Ans : Death Valley

2. ————– is one of the world’s best fishing grounds.

Ans : Grand bank

3. The highest peak in the Andes is ———— on the Chile – Argentina border.

Ans : Mount Aconcagua

4. ————— of the equatorial regions are called the “lungs of the world”.

Ans : The Selvas

5. ———– is also known as the “coffee pot” of the world.

Ans : Minas Gerais and Sao Paulo

III. Match the following

1. Mount McKinleyTropical forests
2. Grand CanyonThe flightless bird
3. EbonyThe Colorado River
4. 4’o Clock Rains6194 m
5. RheaThe equatorial Regions
 Ans : 1 – D, 2 – C, 3 – A, 4 – E, 5 – B

IV. Give Reasons

1. The eastern coast of North America particularly USA enjoys mild climate.

The South and east is usually warm all the year round and the regions around the mouth of the Mississippi- Missouri and the Gulf Coast have summer rain from the North East Trades which blow on-shore in summer.

2. United States of America is known as “Melting Pot”.

United States of America is known as “Melting Pot” where hundreds of different cultures meet, blend and creating a new culture.

3. Though Quito and Amazon basin are in the same latitude Quito enjoys eternal Spring. Whereas Amazon basin is hot.

  • The climate of the continent of South America has been closely influenced by the latitudes, attitudes and the proximity of the Pacific and Atlantic Oceans.
  • It is hot in the Amazon basin as the equator passes through it whereas Quito, situated almost on the same latitude on the Andes, has “Eternal Spring”.
  • That is, it has a pleasant climate throughout the year because of its high altitude at 9,350 feet or 2849.88 meter above the sea level.

4. Peru is one of the world’s largest producers of tropical fish.

  • Peru is one of the world’s largest producers of tropical fish. Here the cool Humboldt Current helps in bring plankton, which is the main food for fishes.
  • Commercial deep-sea fishing off of Peru’s coastal belt of over 3000 km.
  • Peruvian waters normally abound with swordfish, mackerel, yellowfin, pompano, and shark.
  • More than 50 species are caught commercially.
  • There are over 40 fishing ports on the Peruvian coast.
  • Paita and Callao are being the most important centers in Peru.

V. Distinguish between

1. The Rocky mountain and the Appalachian mountain.

 Rocky mountain Appalachian mountain
1. The western part of North America is occupied by long ranges of young fold mountains known as Rocky mountains.The eastern part of North America is formed of old fold Appalachian which is not continuous like the Rockies.
2. The width varies from 110 to 480 km.There are few peaks more than 1800m high
3. The Rocky Mountains are west of the Mississippi River.The Appalachian Mountains are east of the river.

2. The Prairies and the Pampas grassland.

Prairies GrasslandPampas Grassland
1. The temperate grasslands of North America are known as Prairies.The temperate grasslands of South America are known as Pampas.
2. Region – Central USA and Central CanadaRegion – North of Eastern part of Argentina, Uruguay, and Southernmost Brazil.
3. Winter is very cold, Summer is hot and rainfall is moderate.Summer is quite warm and winter is cold and moderate rainfall.
4. Flora – Grasses Flora short grass.
5. Fauna – Coyote, Gophers, Rabbits Prairie Dogs, and BisonFauna – Rhea, Pampas Deer, Jaguar, Camel, Stag, etc.

3. Tundra and Taiga.

1. Region – Northern coast of Canada and Northern Islands.Region – The coniferous forests are found in Alaska and Canada, South Central Alaska, and North Eastern Canada.
2. Climate – Winter is long and severely cold, Summer is short and cool. Rainfall is scanty.Climate – Winter is very cold, Summer is warm and short. Heavy snowfall in winter.
3. Flora – Mosses, Lichens, and Dwarf willowsFlora – Pine, Fir, Cedar, and Spruce.
4. Fauna – Arctic fox, Reindeer, Musk ox, Polar bears, Sable and Blue foxFauna – Beaver, Fox, Sable, Ermine, Skunk, Caribou, and Grizzly Bears.

VI. Put (√) for the correct option

1. Assertion: Cotton grows well in southern and western states of North America.

Reason: : Warm summer with frequent rainfall and the fertile soil which provide favorable conditions.

  1. Both A and R is correct.
  2. A is correct and R is wrong.
  3. A is wrong and R is correct.
  4. Both A and R is wrong

Ans: Both A and R is correct.

2. Assertion: Industries in South America have developed rapidly.

Reason: : The continent lacks infrastructure (especially transport) need for industrialization.

  1. Both A and R is correct.
  2. A is correct and R is wrong.
  3. A is wrong and R is correct.
  4. Both A and R is wrong

Ans : A is wrong and R is correct.

VII. Answer the following:

1. Name the boundaries of North America.

  • North America is surrounded by the Pacific Ocean in the West, the Atlantic Ocean in the east, Arctic Ocean in the north and South America in the south.
  • The North America is joined with the South America by the Isthmus of Panama.
  • The Bering Strait separates North America from Asia.

2. Write a note on Mackenzie River.

The Mackenzie River is the second largest drainage basin of North America. It has it source from Great Slave Lake and drains into Arctic Ocean.

3. What type of fruits are cultivated in North America? Name some of them.

  • Mainly Citrus Fruits are cultivated in Texas, California, Great Lakes regions and St. Lawrence Valley.
  • The important Fruits of North America are Cranberries, Blueberries, Concord Grapes, Strawberries, Gooseberries and the other fruits.

4. Give a short note about the lifestyle of an Eskimos.

  • Eskimos live in the very cold and inhospitable region where plenty of fish varieties are available.
  • They were able to dress themselves in thick warm clothes made of fur, they live in igloos.
  • Their lives were very simple and they could not alter the environment to any extent.
  • They specially designed a house by ice and is known as igloos.

5. Which are the densely populated areas of North America?

Densely populated areas: Eastern part of North America, Great Lakes region, Florida, California, Mexico and Central America are the mostly densely populated areas.

6. Name the physiographic divisions of South America.

On the basis of topographical features, the continent may be divided into the following physiographic divisions:

  • ‘The Andes Mountains
  • The River Basin or Central Plains
  • The Eastern Highlands

7. What is called “4’o clock rains”?

In equatorial regions convectional rain occurs almost daily in the afternoons. It generally occurs at 4pm that’s why it is known as 4’ o Clock Rain.

8. Name the flora and fauna of equatorial forest in South America.

i) Flora :

Rubber, Mahogany, Ebony, Logwood, Brazil nuts and Ceiba.

ii) Fauna:

Anaconda, Armadillo, Piranha, Monkey, Snake, Crocodile and Parrots.

9. What is known as “Estancias”?

The Breeds raised on large pasture lands is known as Estancias. These are divided into several paddocks. Besides this, there are small yards known as corrals where animals are sorted and branded. The owner is the Estanciera who has a number of gauchos.

10. Name the major export of South America.

South America’s major exports are mostly primary commodities such as sugar, coffee, cocoa tobacco, beef, corn, wheat, petroleum, natural gas, linseed, cotton, iron ore, tin and copper. South America’s products include mostly exported to North America and Europe.

VIII. Answer the following in a paragraph

1. Give an account of the climate of North America.

  • The vast latitudinal extent from the Tropics to the Polar Regions makes the climate of North America as varied as that of Asia.
  • Unlike the Himalayas, the Rockies run north to south which do not form climatic barrier and do not prevent the icy winds from the Arctic region and penetrating the central plains which therefore have a very long cold winter and very short hot summer. Precipitation occurs due to cyclonic storms.
  • The Arctic region is cold and mostly dry and has a very short summers and a very long bitterly cold winter.
  • As one proceeds southwards the short summers become warm but the winters are very cold.
  • The central plains have extreme climate from freezing conditions in winter to tropical heat in summer.
  • The South is usually warm all the year round and the regions around the mouth of the Mississippi-Missouri and the Gulf Coast have summer rain from the North East Trades which blow on-shore in summer.
  • The warm moist South Westerlies not only bring rainfall to the North West coast and also keep it warm.
  • The warm Alaskan Current keeps the North West coast ice free.
  • The State of California in USA has a Mediterranean Climate with moist winter and dry summers.

2. Describe the Heavy Engineering Industries in North America.

Heavy Engineering Industries:

  • Industries which require heavy and bulky raw materials using enormous amounts of power, involvement of huge investment and large transport costs are called heavy industries.
  • These industries depend heavily on the Iron and Steel industry.
  • The important Heavy Industries are automobile industries, aircraft industries, ship building industries, Railway Wagon industries and farm equipment industries.
  • USA is the largest producer of automobiles.
  • The important Centers of heavy engineering industries are Detroit, Chicago, Buffalo, Indianapolis, Los Angeles, Saint Louis, Philadelphia, New York, Baltimore, and Atlanta in USA and Windsor in Canada.

3. Describe the drainage system in South America.

  • Owing to the position of the Andes all the great rivers of the continent drain into the Atlantic.
  • The Pacific streams are short and swift but along the coastlands of Peru their waters are used for irrigation and to some extent for hydro-electric power. Amazon is the longest river of South America (6,450km) and is the largest river system in the world. This river has over a thousand of tributaries.
  • The rivers Rio Negro, Madeira and Tapajos are important tributaries.
  • At the point where it enters the sea the river is so wide and powerful that it flows even at a distance of 80 km into the high seas.
  • The Orinoco River originates in the Guiana Highlands and flows northwards into the Caribbean Sea.
  • The river Paraguay has the Parand and Uruguay rivers as the main tributaries which together form and known as the Platte River system.
  • All the rivers are navigable for quite some distance in the interior.

4. Write briefly about the major races in South America.

  • South America contains the world’s most mixed population.
  • Many people in South America are descended from European, especially the Spanish and Portuguese, who begin to arrive during the 15″ century.
  • The descendants of African slaves brought over by the Europeans. Native people still live in the mountain and the rainforests and keeping their own languages and traditions.
  • There are three major races found in South America and are (i) American Indian, (ii) European and (iii) Blacks.
  • The mixed population of Native Indians and Europeans is known as “Mestizo.
  • The mixed population of European and the Blacks is called “Mulato’ and the mixture of Native Indians and Blacks is called “Zambo.
  • The current population of South America is 429, 115, 060 (42.25 cores). Population density of South America is 21 persons per square kilometer.
  • South America is positioned 5″ rank in total population among the continents.

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