Q. There are two statements marked as Assertion (A) and Reason (R). Mark your answer as per the codes provided below:
Assertion (A): North America is larger than South America.
Reason (R): Africa is larger than North America.
Options-
- Both (A) and (R) are true and (R) is the correct explanation of (A).
- Both (A) and (R) are true, but (R) is not the correct explanation of (A).
- (A) is correct but (R) is wrong.
- Both (A) and (R) are false.
Ans. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
Q. What do the five rings in the Olympic symbol represent?
- The five major oceans of the world
- The five major sports in the Olympics
- The five inhabited continents: Africa, America, Asia, Australia, and Europe
- The five Olympic Games held in different cities
Ans. The five inhabited continents: Africa, America, Asia, Australia, and Europe
Q. What is the meaning of the motto “Sam noh Varunah” on the Indian Navy’s emblem, and to which deity is it addressed?
Ans. The motto “Sam noh Varunah” means “Be auspicious to us, O Varuna.” It is addressed to Varuna, a Vedic deity associated with the oceans, the sky, and water.
Q. How do oceans impact weather patterns, and what are the effects on regions like India?
- Oceans bring only mild rain and no storms, benefiting agriculture and reducing damage.
- Oceans cause only destructive storms with no beneficial rain, leading to harm for agriculture and coastal areas.
- Oceans contribute to both beneficial monsoon rains and destructive storms, affecting agriculture and coastal regions.
- Oceans create monsoon rains but do not lead to storms, making them solely beneficial for agriculture.
Ans. Oceans contribute to both beneficial monsoon rains and destructive storms, affecting agriculture and coastal regions.
Q. Locate the five oceans and, in the table below, mark the hemisphere or hemispheres they belong to.
Ocean | Northern Hemisphere | Southern Hemisphere |
Pacific Ocean | Yes | Yes |
Atlantic Ocean | Yes | Yes |
Indian Ocean | Yes | Yes |
Southern Ocean | No | Yes |
Arctic Ocean | Yes | No |
Q. What causes tsunamis, and what impact do they have on coastal areas?
- Tsunamis are caused by strong winds and affect inland areas with minor damage.
- Tsunamis originate from strong earthquakes or volcanic eruptions under the ocean and can cause extensive damage to coastal areas.
- Tsunamis result from heavy rain and flood coastal areas with no significant damage.
- Tsunamis are caused by ocean currents and affect only deep-sea regions without reaching the coast.
Ans. Tsunamis originate from strong earthquakes or volcanic eruptions under the ocean and can cause extensive damage to coastal areas.
Q. Arrange the continents from largest to smallest by their size.
Africa, Antarctica, Asia, Australia, Europe, North America, South America
Ans. Asia, Africa, North America, South America, Antarctica, Europe and Australia.
Q. Write down the list of continents from the smallest to the largest.
Ans. Australia, Europe, Antarctica, South America, North America, Africa and Asia
Q. Which one is larger — North America or South America? Africa or North America? Antarctica or Australia?
- Which one is larger — North America or South America?
Ans. North America is larger than South America.
- Which one is larger — Africa or North America?
Ans. Africa is larger than North America.
- Which one is larger — Antarctica or Australia?
Ans. Antarctica is larger than Australia.
Q. Define the following terms:
- Marine – Related to or found in the oceans and seas.
- Flora – The plant life of a particular region or period of time.
- Fauna – The animal life of a particular region or period of time.
Q. The oceans, therefore, play a crucial role in regulating the climate and sustaining life on Earth. Explain.
Ans.
- Oceans and continents are vital parts of the environment and affect most aspects of our lives, even if we do not notice it.
- We have mentioned that oceans send rain to the continents; this is part of the Earth’s water cycle, which you will further study in Science.
- Without oceans, for instance, there would be no rainfall! The Earth would be a desert.
- Moreover, more than half of the world’s oxygen is produced by the oceans’ flora, which is why they are called ‘the planet’s lungs’.
- The oceans, therefore, play a crucial role in regulating the climate and sustaining life on Earth.
Q. If there is such abundance of water on the planet, why is there so much talk of ‘water scarcity’ or a ‘water crisis’?
Ans.
- Most Water is Saltwater: The majority of Earth’s water is salty ocean water, which isn’t drinkable.
- Limited Freshwater: Freshwater, which we need for drinking and farming, is limited and not evenly distributed. It’s mostly trapped in glaciers, ice caps, or underground.
- Pollution: Many freshwater sources are polluted, making the clean water we have less accessible.
- Overuse: We use more freshwater than can be naturally replenished, leading to shortages.
- Climate Change: Changes in climate can affect where and how much freshwater is available.
These issues make it challenging to access enough clean water, even though there is a lot of water on the planet.
Q. What are oceans and continents? What are their names and their distribution?
Ans.
- The largest water bodies we see on the globe are called ‘oceans’. There are five oceans. They are Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, Arctic Ocean.
- The oceans together hold most of the water available on the planet. But this seawater is salty and unfit for consumption by most land animals, including humans.
- On the other hand, freshwater makes up a very small proportion of the planet’s water resources.
- It is found in glaciers, rivers, lakes, in the atmosphere and also underground (the last is called ‘groundwater’).
- A large body of land is called a ‘landmass’, and a large continuous expanse of land is called a ‘continent’. There are seven continents. They are Asia, Africa, North America, South America, Antarctica, Europe and Australia.
Q. Explain the following terms: a) Continent b) Ocean c) Island
Ans.
- A large body of land is called a ‘landmass’, and a large continuous expanse of land is called a ‘continent’.
- The largest water bodies we see on the globe are called ‘oceans.
- Island – Landmasses surrounded by water on all sides, they are called islands
Q. Name the five oceans of the world.
Ans. The Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern (or Antarctic) Ocean
Q. Explain why marine life is considered to be highly diverse, using examples to support your explanation.
Ans.
- Many plant and animal species can be found across multiple oceans.
- The marine flora includes tiny plants called algae and all kinds of seaweeds; the marine fauna consists of thousands of species of colourful fish, dolphins, whales, and countless mysterious deep-sea creatures.
- Each part of the ocean, from the sun-lit surface to the dark depths, has its own diverse life forms.
Q. Read the passage given below and answer the following questions.
On 26 December 2004, India and another 13 countries around the Indian Ocean were struck by a powerful tsunami caused by an earthquake in Indonesia. More than two lakh people lost their lives. In India, the Andaman and Nicobar Islands (see Fig. 2.4 above, and also the subsection ‘Islands’ further below) and the coasts of Tamil Nadu and Kerala were severely affected and suffered much damage and loss of life. Such tsunamis are rare but very destructive. Luckily, they can often be detected before they hit a coast. Many countries collaborate in such ‘early warning systems’. There is, in particular, an Indian Ocean Tsunami Warning System, to which many countries, including India, contribute. This helps to take measures to protect lives and property. Events that lead to loss of life and property are handled under disaster management. India has its own ‘National Disaster Management Authority’ to deal with all kinds of disasters.
- On which date did the powerful tsunami strike India and 13 other countries around the Indian Ocean?
A) 26 December 2004
B) 1 January 2005
C) 15 November 2004
D) 5 December 2004
- What caused the tsunami that struck the Indian Ocean region on 26 December 2004?
A) A volcanic eruption in the Pacific Ocean
B) A strong earthquake in Indonesia
C) Heavy rainfall in India
D) A cyclone in the Indian Ocean
- Which Indian regions were severely affected by the 2004 tsunami?
A) Delhi and Mumbai
B) Gujarat and Rajasthan
C) Andaman and Nicobar Islands, Tamil Nadu, and Kerala
D) Uttar Pradesh and Punjab
- What system helps detect tsunamis and protect lives and property in affected regions?
A) National Weather Service
B) Earthquake Prediction System
C) Indian Ocean Tsunami Warning System
D) Global Flood Alert System
Q. On which sides of India are the Arabian Sea and the Bay of Bengal located?
Ans. The Arabian Sea is located to the west of India, and the Bay of Bengal is located to the east of India.
Q. Describe the major island groups of India and their locations. What are the main accomplishments of the Indian Antarctica Programme? Discuss the base stations and the research conducted there.
Ans.
- India has more than 1,300 small islands! Those include two major groups — Andaman and Nicobar Islands in the Bay of Bengal and Lakshadweep Islands in the Arabian Sea. Greenland is the largest island in the world.
- Since 1981, the Indian Antarctica Programme has been exploring Antarctica, a continent with a very cold climate and harsh environment. In 1983, India established its first scientific base station there, called ‘Dakshin Gangotri’ (two more bases were established later).
- About 40 teams of Indian scientists have conducted research in this faraway region, especially on the evolution of climate and environment. The settlement where the scientists live has a library and even a post office!
Q. Explain the different ways oceans have affected human history. Explain with the help of examples.
Ans. Oceans have deeply impacted humanity in many other ways.
- From early times, people have used oceans and seas to migrate to other regions, to trade in all kinds of goods, to conduct military campaigns, and as a source of food through fishing.
- Oceans have also nourished the cultures of coastal people all over the world.
- Almost all of them have tales and legends about the sea, sea gods and goddesses, sea monsters and treasures from the sea — the oceans’ dangers but also their blessings.
Q. What are the major roles of the ocean in supporting life on Earth? Also, identify two human-induced problems that contribute to the decline of marine environments.
Ans.
- The United Nations has designated June 8 as World Oceans Day to “remind us all of the major role the ocean plays in everyday life. It serves as the lungs of our planet, a major source of food and medicine and a critical part of the biosphere.”
- Scientific studies have shown how the oceans are polluted by human activity — we throw several million tonnes of plastic waste into the oceans every year, choking marine life.
- There are several other forms of pollution. As a result, the marine environment is under threat. Overfishing (excessive fishing) is another cause for the decline of marine life.
- It is our collective responsibility to protect oceans for the future of the planet and of humanity
Q. Map work
On an outline map of the world mark and label all the continents and oceans.