Prepare for the ISSO Olympiad with 25 olympiad-level MCQs on Oceans and Continents, covering the five oceans, seven continents, islands, tsunamis, and ocean life — complete with answers and detailed explanations for Social Science students.

Section A: Questions

Q1. Approximately what fraction of the Earth’s surface is covered by water?

1. One-half
2. Two-thirds
3. Three-fourths
4. Nine-tenths

Q2. Which of the following correctly defines a ‘continent’ as distinguished from a ‘landmass’?

1. Any body of land surrounded by water
2. A large continuous expanse of land
3. A small piece of land surrounded by water on all sides
4. Any landmass located in the Southern Hemisphere

Q3. Which hemisphere holds proportionally more water, based on the polar-view maps in the chapter?

1. Northern Hemisphere
2. Southern Hemisphere
3. Both hold exactly equal amounts
4. Neither — water is evenly distributed

Q4. Which of these is NOT listed among the five conventional oceans in the chapter?

1. Arctic Ocean
2. Southern Ocean
3. Caribbean Ocean
4. Indian Ocean

Q5. According to the chapter, why are the boundaries between the five oceans considered mere conventions?

1. Because seawater constantly flows across different oceans and marine life is not confined by these lines
2. Because oceans dry up and reform every year
3. Because only sailors agree on where one ocean ends
4. Because the five oceans have identical depths

Q6. Ranking the oceans from largest to smallest, which sequence is correct?

1. Atlantic > Pacific > Indian > Southern > Arctic
2. Pacific > Atlantic > Indian > Southern > Arctic
3. Pacific > Indian > Atlantic > Arctic > Southern
4. Indian > Pacific > Atlantic > Southern > Arctic

Q7. The Indian Ocean is bordered by which three continents (apart from the Southern Ocean to its south)?

1. Asia to the north, Africa to the west, Australia to the east
2. Europe to the north, America to the west, Antarctica to the east
3. Asia to the south, Africa to the north, Australia to the west
4. Australia to the north, Asia to the west, Africa to the east

Q8. On either side of India, the Indian Ocean forms two named parts. What are they?

1. The Persian Gulf and the Red Sea
2. The Arabian Sea (west) and the Bay of Bengal (east)
3. The Bay of Bengal (west) and the Arabian Sea (east)
4. The Andaman Sea and the Laccadive Sea

Q9. A student claims the Earth has exactly seven continents and that this is the only scientifically correct count. Based on the chapter, why is this claim flawed?

1. Because there are actually nine continents
2. Because continents can be counted as four, five, six, or seven depending on how landmasses like Europe-Asia or North-South America are grouped
3. Because continents do not really exist
4. Because oceans should also be counted as continents

Q10. Geologists often combine Europe and Asia into a single continent. What is this combined landmass called?

1. Pangea
2. Eurasia
3. Afro-Eurasia
4. Laurasia

Q11. In the ‘four continents’ count given in the chapter, how are the landmasses grouped?

1. Africa-Eurasia, America, Antarctica, Australia
2. Africa, Eurasia, America, Antarctica
3. Asia, Europe, Africa, America
4. Eurasia, Africa, Antarctica, America

Q12. The five Olympic rings symbolise the coming together of athletes from how many inhabited continents, and which ones?

1. Six continents, including Antarctica
2. Five continents — Africa, America, Asia, Australia, and Europe
3. Four continents only
4. Seven continents, treating North and South America separately

Q13. What is the key distinguishing feature that makes a piece of land an ‘island’ rather than a continent?

1. Islands are always found in the Southern Hemisphere
2. Islands must be uninhabited
3. Islands are surrounded by water on all sides but are much smaller than continents, which are also surrounded by water but too large to be classed as islands
4. Islands never have any plant or animal life

Q14. Which is the largest island in the world, and what comparison does the chapter use to convey its size?

1. Madagascar — equal in size to the whole of India
2. Greenland — equal in area to the 10 largest states of India combined
3. Borneo — equal in size to Australia
4. Sumatra — equal in size to Europe

Q15. India’s more than 1,300 small islands are grouped into two major clusters. What are they and in which seas are they located?

1. Lakshadweep Islands in the Bay of Bengal; Andaman and Nicobar Islands in the Arabian Sea
2. Andaman and Nicobar Islands in the Bay of Bengal; Lakshadweep Islands in the Arabian Sea
3. Andaman Islands in the Arabian Sea; Nicobar Islands in the Bay of Bengal
4. Lakshadweep Islands in the Southern Ocean; Nicobar Islands in the Pacific

Q16. What natural process most directly causes a tsunami, according to the chapter?

1. Strong surface winds blowing over the open ocean
2. A strong earthquake or volcanic eruption at the bottom of the ocean
3. Excessive rainfall during the monsoon
4. Melting of polar ice caps

Q17. The devastating tsunami of 26 December 2004 that struck India and 13 other countries around the Indian Ocean originated from an earthquake in which country?

1. India
2. Sri Lanka
3. Indonesia
4. Thailand

Q18. What is the main purpose of the Indian Ocean Tsunami Warning System mentioned in the chapter?

1. To predict monsoon rainfall patterns
2. To enable participating countries to detect tsunamis early and take measures to protect lives and property
3. To measure the salinity of seawater
4. To track migratory patterns of marine species

Q19. Which Indian government body is responsible for handling events that lead to loss of life and property from disasters like tsunamis and cyclones?

1. Indian Meteorological Society
2. National Disaster Management Authority
3. Central Water Commission
4. Indian Coast Guard Council

Q20. India’s first scientific base station in Antarctica, established in 1983, was named:

1. Bharati
2. Maitri
3. Dakshin Gangotri
4. Himadri

Q21. Why are oceans sometimes referred to as ‘the planet’s lungs’?

1. Because they absorb all of the world’s carbon dioxide
2. Because more than half of the world’s oxygen is produced by the oceans’ flora
3. Because they regulate human breathing rates near coastlines
4. Because they are shaped like a pair of lungs on the world map

Q22. The Indian Navy’s motto ‘Sam noh Varunah’ is an invocation to which deity, and what does it mean?

1. Indra — ‘Grant us rain’
2. Varuna — ‘Be auspicious to us, O Varuna’
3. Agni — ‘Protect us with fire’
4. Surya — ‘Give us light’

Q23. Which of the following is described in the chapter as freshwater sources, as opposed to the salty water of oceans?

1. Glaciers, rivers, lakes, atmosphere, and groundwater
2. Seas, bays, and gulfs
3. The Pacific and Atlantic Oceans only
4. Coral reefs and estuaries

Q24. Besides supplying rainfall through the water cycle, which of these is mentioned as a historical way in which oceans have impacted humanity?

1. Migration, trade, military campaigns, and fishing
2. Only recreational swimming
3. Providing electricity through tidal dams built in ancient times
4. Serving purely as territorial borders with no economic use

Q25. According to the ‘Don’t Miss Out’ box on World Oceans Day, which date has the United Nations designated for this observance, and why?

1. 8 June, to highlight the ocean’s role as the planet’s lungs, a food and medicine source, and part of the biosphere
2. 22 April, to mark the founding of the United Nations Environment Programme
3. 5 June, to commemorate the first tsunami warning system
4. 14 November, to celebrate the discovery of the Southern Ocean

 

Section B: Answer Key & Explanations

Q1. Correct Answer: C

Explanation: The chapter states that land covers a little over one-fourth of the globe, which means water covers almost three-fourths of the Earth’s surface — this is why the Earth is called the ‘blue planet’.

Q2. Correct Answer: B

Explanation: The text defines a large body of land as a ‘landmass’, while a large continuous expanse of land is specifically called a ‘continent’. So all continents are landmasses, but not all landmasses are continents.

Q3. Correct Answer: B

Explanation: The maps viewed from above the North and South Poles show that oceans and continents are not distributed equally between the hemispheres; the Southern Hemisphere is dominated far more by ocean, while the Northern Hemisphere has proportionally more land.

Q4. Correct Answer: C

Explanation: The five oceans named are the Pacific, Atlantic, Indian, Arctic, and Southern (or Antarctic) Ocean. The Caribbean is a sea, not one of the five recognised oceans.

Q5. Correct Answer: A

Explanation: The chapter explains that although five oceans are listed, they are not truly separate — seawater flows continuously between them, and many marine species are found across multiple oceans, so the dividing lines are conventions, not natural boundaries.

Q6. Correct Answer: B

Explanation: The chapter states the Pacific Ocean is the largest, followed by the Atlantic, then the Indian Ocean (third largest), the Southern Ocean (fourth), and the Arctic Ocean is the smallest.

Q7. Correct Answer: A

Explanation: The chapter states the main limits of the Indian Ocean are Asia to the north, Africa to the west, and Australia to the east, with the Southern Ocean forming its boundary to the south.

Q8. Correct Answer: B

Explanation: The chapter clearly states that the Arabian Sea lies to the west of India and the Bay of Bengal lies to its east, both being parts of the Indian Ocean.

Q9. Correct Answer: B

Explanation: The chapter shows that the continent count varies from four to seven depending on whether Europe and Asia are combined as ‘Eurasia’, whether North and South America are combined, and whether Africa and Eurasia are combined. Seven is simply the most widely adopted count, not the only valid one.

Q10. Correct Answer: B

Explanation: The chapter notes that although Europe and Asia are generally treated as two continents for historical and cultural reasons, geologists often regard them as a single continent called ‘Eurasia’, since they form one continuous landmass.

Q11. Correct Answer: A

Explanation: The four-continent count combines Africa and Eurasia into one, and North and South America into one, giving: Africa-Eurasia, America, Antarctica, and Australia.

Q12. Correct Answer: B

Explanation: The chapter states the Olympic rings were chosen to represent five inhabited continents: Africa, America, Asia, Australia, and Europe. Antarctica is excluded since it has no permanent population.

Q13. Correct Answer: C

Explanation: The chapter explains that continents are technically also surrounded by water, but because of their enormous size, they are not classified as islands. Islands are the smaller pieces of land left out of the continents, surrounded by water on all sides.

Q14. Correct Answer: B

Explanation: The chapter states that Greenland is the largest island in the world and that you would have to add together the areas of the 10 largest states of India to match its size.

Q15. Correct Answer: B

Explanation: The chapter states the Andaman and Nicobar Islands lie in the Bay of Bengal (east of India), while the Lakshadweep Islands lie in the Arabian Sea (west of India).

Q16. Correct Answer: B

Explanation: The chapter defines a tsunami as a huge, powerful wave generally caused by a strong earthquake or a volcanic eruption occurring at the bottom of the ocean, distinguishing it from wind-driven storms like cyclones.

Q17. Correct Answer: C

Explanation: The chapter states that the 2004 tsunami was caused by an earthquake in Indonesia, and it struck India along with 13 other countries around the Indian Ocean, severely affecting the Andaman and Nicobar Islands and the coasts of Tamil Nadu and Kerala.

Q18. Correct Answer: B

Explanation: The chapter explains that many countries, including India, contribute to this early warning system so that tsunamis can be detected before they hit a coast, helping to protect lives and property — an example of disaster management.

Q19. Correct Answer: B

Explanation: The chapter states that events causing loss of life and property are handled under ‘disaster management’, and India has its own National Disaster Management Authority to deal with all kinds of disasters.

Q20. Correct Answer: C

Explanation: The chapter states that under the Indian Antarctica Programme (running since 1981), India established its first scientific base station in Antarctica in 1983, called ‘Dakshin Gangotri’, with two more bases established later.

Q21. Correct Answer: B

Explanation: The chapter explains that more than half of the world’s oxygen is produced by the oceans’ flora (such as algae), which is why oceans are called ‘the planet’s lungs’ and play a crucial role in sustaining life on Earth.

Q22. Correct Answer: B

Explanation: The chapter states that the Indian Navy’s emblem carries the motto ‘Sam noh Varunah’, an invocation to Varuna — a Vedic deity associated with the oceans, sky, and water — meaning ‘Be auspicious to us, O Varuna.’

Q23. Correct Answer: A

Explanation: The chapter notes that seawater is salty and unfit for consumption, while freshwater — found in glaciers, rivers, lakes, the atmosphere, and underground as groundwater — makes up only a small proportion of the planet’s water resources.

Q24. Correct Answer: A

Explanation: The chapter states that from early times, people have used oceans and seas to migrate to other regions, trade goods, conduct military campaigns, and obtain food through fishing, while also nourishing coastal cultures with legends of sea gods and sea monsters.

Q25. Correct Answer: A

Explanation: The chapter quotes the United Nations designation of 8 June as World Oceans Day, meant to remind people of the ocean’s major role as the lungs of the planet, a major source of food and medicine, and a critical part of the biosphere.