Q1. Explain the following terms:
(a) Continent – A continent is a very large continuous landmass surrounded by oceans. There are seven continents on Earth: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.
(b) Ocean – Oceans are vast bodies of salt water covering about three-fourths of the Earth’s surface. The five main oceans are the Pacific, Atlantic, Indian, Arctic, and Southern Oceans.
(c) Island – An island is a piece of land surrounded by water on all sides but smaller than a continent. Example: Greenland, Andaman and Nicobar Islands.
Q2. Let us draw – Without looking at the maps in this chapter, draw the continents free hand on a sheet of paper and colour them. Then compare your drawing with the map of oceans and continents in the chapter.
Answer (Guidance for students):
- Draw a rough sketch of the world map.
- Colour the continents in different colours (e.g., Asia – yellow, Africa – green, North America – pink, South America – orange, Europe – purple, Australia – red, Antarctica – blue).
- Colour all oceans in blue.
- Then compare with the map in your book and check shapes, positions, and sizes.
Q3. Let us do – On the outline map of the world given below, label all the continents and oceans.
Answer (Guidance):
- Mark and label:
- Continents: Asia, Africa, North America, South America, Antarctica, Europe, Australia.
- Oceans: Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean, Southern Ocean.
Q4. Solve this crossword.
Across
- Oxygen
- Continent
- Asia
- Plastic
- Antarctica
Down
2. Greenland
4. Tsunami
5. Australia
7. Pacific
9. Island
Q4. Name the seven continents in order of size (largest to smallest).
Answer:
- Asia
- Africa
- North America
- South America
- Antarctica
- Europe
- Australia
Q5. What are tsunamis and how are they caused?
Answer (60–70 words):
A tsunami is a giant ocean wave caused by underwater earthquakes, volcanic eruptions, or landslides. The sudden movement of the sea floor displaces a huge amount of water, creating powerful waves that travel across the ocean. When they reach shallow coastal areas, these waves rise high and cause destruction. The 2004 Indian Ocean tsunami is an example, which affected Tamil Nadu, Kerala, and the Andaman & Nicobar Islands.
Q6. What is the difference between an island and a continent?
Answer:
- Continent: Very large continuous landmass (e.g., Asia, Africa).
- Island: Smaller landmass surrounded by water (e.g., Greenland, Andaman).
Q7. Why is saving oceans important for our future?
Answer (80–90 words):
Oceans are called the “lungs of the planet” because they produce most of the oxygen we breathe. They also provide food, medicines, water cycle balance, and climate control. However, pollution, plastic waste, and overfishing are threatening marine life. If we don’t protect oceans, it will harm biodiversity and human survival. Saving oceans is necessary for a healthy planet and for future generations.
Extra Questions – Oceans and Continents
Q1. Why is the Earth called the “blue planet”?
Answer:
The Earth is called the blue planet because nearly three-fourths of its surface is covered with water. From space, the oceans give the Earth a bluish appearance, making it look mostly blue.
Q2. Which is the largest and which is the smallest ocean?
Answer:
- The Pacific Ocean is the largest ocean.
- The Arctic Ocean is the smallest ocean.
Q3. How do oceans influence the climate of the Earth?
Answer (70–80 words):
Oceans store and distribute heat across the planet. They bring rainfall to the continents through the water cycle and regulate temperature by absorbing heat. For example, the Indian Ocean gives rise to monsoon rains, which are vital for agriculture in India. Oceans also produce more than half of the world’s oxygen, making them essential for life and climate balance.