How to Use This Page
This page provides complete exercise solutions for Chapter 1: Exploring Continents – North America and South America from the Samacheer Kalvi 7th Social Science textbook (Geography, Term 3). Read each question, attempt it on your own first, then compare with the answers below. Use the Key Concepts section for a quick revision before exams.
Key Concepts (Quick Recap)
- North America: Bordered by Pacific Ocean (west), Atlantic Ocean (east), Arctic Ocean (north), South America (south)
- South America: Connected to North America via the Isthmus of Panama; 12 degrees North to 55 degrees South
- Key Straits/Landforms: Bering Strait (separates N. America from Asia), Isthmus of Panama (connects N. and S. America)
- Mountains: Rockies and Coast Range (Western Cordilleras), Appalachian Mountains (east), Andes (longest mountain chain)
- Rivers: Mississippi-Missouri (longest in N. America), Amazon (longest in S. America), Mackenzie, Orinoco, Parana
- Climate Zones: Tundra, Taiga, Prairies, Mediterranean, Desert (N. America); Equatorial, Tropical, Temperate (S. America)
- 4'o Clock Rains: Convectional rains in equatorial regions, especially Amazon basin
- Selvas: Equatorial forests of South America, called "lungs of the world"
- Key Terms: Isthmus (narrow land joining two landmasses), Strait (narrow water joining two water bodies)
Exercise Solutions
I. Choose the Correct Answer (MCQs)
Q1. The ________ separates North America from Asia.
- a) Bering Strait ✓
- b) Palk Strait
- c) Malacca Strait
- d) Gibraltar Straits
Q2. ________ is known as the "sugar bowl of the world".
- a) Mexico
- b) USA
- c) Canada
- d) Cuba ✓
Q3. ________ are the longest rivers in North America.
- a) The Mississippi and Missouri rivers ✓
- b) The Mackenzie river
- c) The St. Lawrence river
- d) The Colorado river
Q4. ________ is the longest mountain chain in the world.
- a) The Andes ✓
- b) The Rockies
- c) The Himalayas
- d) The Alps
Q5. ________ basin gets rainfall every day because of its equatorial location.
- a) The Mackenzie
- b) The Orinoco
- c) The Amazon ✓
- d) The Parana
Q6. North America was discovered by Christopher Columbus in ________
- a) 1492 ✓
- b) 1592
- c) 1493
- d) 1595
Q7. ________ was introduced by European settlers in North America.
- a) Maize
- b) Barley
- c) Sugarcane
- d) Wheat ✓
Q8. ________ is the native food crop of North America.
- a) Maize ✓
- b) Barley
- c) Sugarcane
- d) Wheat
Q9. ________ grows well in Southern and Western States.
- a) Maize
- b) Barley
- c) Sugarcane
- d) Cotton ✓
Q10. ________ beet is used for making sugar.
- a) Sugar ✓
- b) Flour
- c) Chips
- d) Fries
Q11. The USA is the largest producer of ________
- a) Atomic power
- b) Solar power
- c) Automobile ✓
- d) Tyre
Q12. Toronto, Cornwall, and Kingston are the major ________ centres in Canada.
- a) Textile industry ✓
- b) Iron and steel industry
- c) Paper industry
- d) None
Q13. ________ are important ports on the West Coast of North America.
- a) San Francisco ✓
- b) New York
- c) Philadelphia
- d) puledra
Q14. ________ are animals typically found only in South America.
- a) Anaconda
- b) Llamas ✓
- c) Piranha
- d) Raccoons
Q15. ________ are the most important crops in South America.
- a) Coffee and Cocoa ✓
- b) Tea
- c) Brazil
- d) Rubber
II. Fill in the Blanks
1. Death Valley 86 m below sea level is the lowest part of the continent of North America. 2. Grand Bank is one of the world's best fishing grounds. 3. The highest peak in the Andes is Mount Aconcagua on the Chile-Argentina border. 4. The Selvas of the equatorial regions are called the "lungs of the world". 5. Minas Gersals and Sao Paulo is also known as the "coffee pot" of the world. 6. Isthmus is a narrow stretch of land joining two large landmasses. 7. Strait is a narrow stretch of water joining two large water bodies. 8. The Rockies and the Coast Range are together called the Western Cordilleras. 9. The Mississippi and Missouri rivers are the longest rivers in North America. 10. The Big Muddy erodes a lot of sand and mud as it rushes down the mountains. 11. Both Canada and the USA are the major exporters of wheat more than other countries of the world. 12. Barley and Oats are used as cattle fodder. 13. Soya beans is used for extraction of edible oil. 14. The Isthmus of Panama in the North West connects South America with North America. 15. Amazon is the greatest river of South America. 16. The Piranha found in the Amazon is a fierce flesh-eating fish. 17. Brazil has the second-largest iron ore deposits in the world after Russia. 18. Chile is the third-largest producer of copper in the world. 19. Brazil is the third-largest bauxite producing country. 20. Moderate populated areas are Paraguay, Chile, and Uruguay.
III. Match the Following
Match A (Main Exercise):
| A | B | Answer |
|---|---|---|
| 1. Mount McKinley | a) Tropical forests | 1-d) 6194 m |
| 2. Grand Canyon | b) The flightless bird | 2-c) The Colorado River |
| 3. Ebony | c) The Colorado River | 3-a) Tropical forests |
| 4. 4'o Clock Rains | d) 6194 m | 4-e) The equatorial regions |
| 5. Rhea | e) The equatorial regions | 5-b) The flightless bird |
Match B (Additional Exercise):
| A | B | Answer |
|---|---|---|
| 1. Antarctica | a) Active Volcano | 1-e) Mount Vinson Massif |
| 2. Mississippi | b) Great lakes | 2-b) Great lakes |
| 3. Grand Banks | c) Biggest bird | 3-d) Petroleum reserves |
| 4. Cordilleras | d) Petroleum reserves | 4-a) Active Volcano |
| 5. Condor | e) Mount Vinson Massif | 5-c) Biggest bird |
IV. Give Reasons
Q1. The eastern coast of North America, particularly the USA, enjoys a mild climate. The south and east are usually warm year-round. Regions around the mouth of the Mississippi-Missouri and Gulf Coast receive summer rain from the Northeast Trades which blow onshore in summer.
Q2. The United States of America is known as the "Melting Pot". The USA is called a "Melting Pot" because hundreds of different cultures meet, blend, and create a new culture. People from various countries have migrated to the USA, bringing their traditions, languages, and customs, which all blend together.
Q3. Though Quito and the Amazon basin are in the same latitude, Quito enjoys eternal Spring whereas the Amazon basin is hot. South America's climate is influenced by latitudes, altitudes, and proximity to oceans. The Amazon basin is hot because the equator passes through it. Quito, situated on the Andes at approximately 2,850 m above sea level, has a pleasant "Eternal Spring" climate throughout the year due to its high altitude, which offsets the equatorial heat.
Q4. Peru is one of the world's largest producers of tropical fish. The cool Humboldt Current brings plankton, which is the main food for fishes. Commercial deep-sea fishing occurs along Peru's coastal belt spanning over 3,000 km, making Peru one of the world's largest producers of tropical fish.
Q5. The Mississippi River has been given the nickname "The Big Muddy". The Mississippi River erodes a lot of sand and mud as it rushes down the mountains, hence the nickname "The Big Muddy."
Q6. South America is also known as Latin America. Together with Central America, South America was discovered and colonised mostly by the Latins — the Spanish and Portuguese — hence the name Latin America.
V. Distinguish Between
VI. Assertion and Reason
Q1. A: Cotton grows well in southern and western states of North America. R: Warm summer with frequent rainfall and fertile soil provide favourable conditions.
- a) Both A and R are correct ✓
- b) A is correct and R is wrong
- c) A is wrong and R is correct
- d) Both A and R are wrong
Q2. A: Industries in South America have developed rapidly. R: The continent lacks infrastructure (especially transport) needed for industrialization.
- a) Both A and R are correct
- b) A is correct and R is wrong
- c) A is wrong and R is correct ✓
- d) Both A and R are wrong
Q3. Evaluate the following: 1. Joining two large landmasses — Isthmus ✓ 2. Africa — Mount Kilimanjaro ✓ 3. America Prairie Grassland — High production of wheat ✓ 4. Bagland island — Goat (incorrect pairing) 5. Argentina — samba dance (incorrect; samba is from Brazil)
VII. Very Short Answers (1-2 sentences)
Q1. Name the boundaries of North America. North America is surrounded by the Pacific Ocean in the west, the Atlantic Ocean in the east, the Arctic Ocean in the north, and South America in the south.
Q2. Write a note on the Mackenzie River. The Mackenzie River is the second-largest drainage basin of North America. It has its source from Great Slave Lake and drains into the Arctic Ocean.
Q3. What type of fruits are cultivated in North America? Name some. Important fruits cultivated include Cranberries, Blueberries, Concord Grapes, Strawberries, and Gooseberries.
Q4. Give a short note about the lifestyle of Eskimos. Eskimos live in very cold regions where plenty of fish are available. They dress in thick warm clothes made of fur and live in igloos — houses specially designed from ice. Their lives were simple and they could not alter the environment to any extent.
Q5. Which are the densely populated areas of North America? The Eastern part, the Great Lakes region, Florida, California, Mexico, and Central America are the most densely populated areas.
Q6. Name the physiographic divisions of South America. The three physiographic divisions are: the Andes Mountains, the River Basin or Central Plains, and the Eastern Highland.
Q7. What is called "4'o clock rains"? The Amazon basin gets rainfall every day due to its equatorial location. The regions around the Equator receive "4'o Clock Rains," which are convectional rains occurring in the afternoon.
Q8. Name the flora and fauna of equatorial forest in South America. Flora: Rubber, Mahogany, Ebony, Logwood, Brazil nuts, and Ceiba. Fauna: Anaconda, Armadillo, Piranha, Monkey, Snake, Crocodile, and Parrot.
Q9. What is known as "Estancias"? Estancias are large pasture lands in South America where breeds are raised. They are divided into paddocks, with small yards called corrals where animals are sorted and branded.
Q10. Name the major exports of South America. Major exports include sugar, coffee, cocoa, tobacco, beef, corn, wheat, petroleum, natural gas, linseed, cotton, iron ore, tin, and copper, mostly exported to North America and Europe.
Q11. What is "The Big Muddy"? The Mississippi River is nicknamed "The Big Muddy" because it erodes a lot of sand and mud as it rushes down the mountains.
Q12. Name the physical divisions of North America. The four physical divisions are: the Rocky Mountains, the Great Plains, the Appalachian Highlands, and the Coastal Plain.
Q13. Write a short note on the Mississippi River. The Mississippi and Missouri rivers are the longest rivers in North America, forming the fourth longest river system in the world, stretching over 6,114 km from Montana to the Gulf of Mexico.
VIII. Detailed Answers (Paragraph-length)
Q1. Give an account of the climate of North America. The vast latitudinal extent from tropics to polar regions makes North America's climate as varied as Asia's. The Rockies run north-south and do not form a climatic barrier, so icy Arctic winds penetrate the central plains, creating very long cold winters and very short hot summers. Precipitation occurs through cyclonic storms. The Arctic region is cold and mostly dry with very short summers and bitterly cold winters. Moving southward, summers become warm but winters remain very cold. The central plains have extreme climates — from freezing winters to tropical heat in summer. The south is usually warm year-round; regions around the Mississippi-Missouri mouth and Gulf Coast get summer rain from Northeast Trades blowing onshore. The warm moist South Westerlies bring rainfall to the Northwest coast and keep it warm. The warm Alaskan Current keeps the Northwest coast ice-free. California has a Mediterranean climate with moist winters and dry summers.
Q2. Describe the Heavy Engineering Industries in North America. Heavy industries require heavy and bulky raw materials, enormous power, huge investment, and large transport costs. They depend heavily on the Iron and Steel industry. Important heavy industries include automobile, aircraft, shipbuilding, railway wagon, and farm equipment industries. The USA is the largest automobile producer in the world. Important centres include Detroit, Chicago, Buffalo, Indianapolis, Los Angeles, Saint-Louis, Philadelphia, New York, Baltimore, and Atlanta (in the USA), and Windsor (in Canada). Detroit is famously known as the "Motor City" or "Automobile Capital of the World."
Q3. Describe the drainage system in South America. Due to the Andes' position along the western edge, all great rivers of South America drain into the Atlantic Ocean. Pacific streams are short and swift but are used for irrigation and hydroelectric power along Peru's coastlands. The Amazon (6,450 km) is the longest river in South America and the largest river system in the world, with over a thousand tributaries — important ones include the Rio Negro, Madeira, and Tapajos. At its mouth, the river is so powerful it flows 80 km into the high seas. The Orinoco originates in the Guiana Highlands and flows north into the Caribbean Sea. The Paraguay has the Parana and Uruguay rivers as its main tributaries, together forming the Platte River system. All rivers are navigable for considerable distances inland.
Q4. Write briefly about the major races in South America. South America has the world's most mixed population. Many are descended from Europeans, especially Spanish and Portuguese who arrived in the 15th century. Descendants of African slaves brought by Europeans also form part of the population. Native people still live in mountains and rainforests, maintaining their own languages. The mixed population of native Indians and Europeans is called "Mestizo." Europeans mixed with Blacks are called "Mulato." Native Indians mixed with Blacks are called "Zambo." This rich racial diversity gives South America its unique cultural character.
Common Mistakes
1. Confusing Isthmus and Strait: An Isthmus is a narrow stretch of land joining two landmasses; a Strait is a narrow stretch of water joining two water bodies. 2. Mixing up mountain ranges: The Rockies are in North America; the Andes are in South America. The Appalachians are in eastern North America. 3. Confusing Prairies and Pampas: Prairies are in North America; Pampas are in South America. Both are grasslands but on different continents. 4. Wrong capital of Brazil for "coffee pot": It is Minas Gersals and Sao Paulo, not the capital Brasilia. 5. Forgetting the altitude effect on climate: Quito is cool ("Eternal Spring") not because of latitude but because of high altitude (2,850 m). 6. Misidentifying native vs. introduced crops: Maize is native to North America; wheat was introduced by European settlers. 7. Confusing population terms: Mestizo = Indian + European; Mulato = European + Black; Zambo = Indian + Black.
Exam Checklist
- [ ] Can you name the boundaries and physical divisions of North America?
- [ ] Can you distinguish between the Rockies and the Appalachians?
- [ ] Can you explain the climate zones of North America?
- [ ] Do you know the difference between Tundra and Taiga?
- [ ] Can you list the major rivers of both continents (Mississippi, Amazon, Orinoco, Parana)?
- [ ] Can you explain why Quito is cool while the Amazon basin is hot (altitude vs. latitude)?
- [ ] Do you know what "4'o Clock Rains" are?
- [ ] Can you define Isthmus and Strait with examples?
- [ ] Can you explain the drainage system of South America?
- [ ] Do you know the racial terms: Mestizo, Mulato, Zambo?
- [ ] Can you name the key industries and crops of both continents?
- [ ] Can you explain why the USA is called the "Melting Pot"?
- [ ] Can you explain why Peru is a major fish producer (Humboldt Current)?