Write about the major oceans of the world.
There are four major oceans in the world—the Pacific Ocean the Atlantic Ocean, the Indian Ocean and the Arctic Ocean.
1.The Pacific Ocean. It is the largest ocean and is spread over one-third of the earth. Mariana Trench, the deepest part of the earth, lies under the Pacific Ocean. This ocean is circular in shape. Asia, Australia, North and South Americas surround it.
2.The Atlantic Ocean. It is the second largest ocean in the world. It is ‘S' shaped. It is flanked by the North and South Americas on the Western side and Europe and Africa on the eastern side. The coastline of this ocean is highly indented. It is the ideal location for natural harbours and ports. Commercially, it is the busiest ocean.
3.The Indian Ocean. It is the only ocean named after country, that is, India. The shape of the ocean is triangular. It is bound by Asia in the north, by Africa in the west and by Australia in the east.
4.The Arctic Ocean. It is located within the Arctic Circle and surrounds the North Pole. It is connected with the Pacific Ocean by a narrow stretch of shallow water known as Berring Strait. See the map given in the previous question.
Give an account of the composition of atmosphere. Also discuss the importance of the components. [V. Imp.]
Answer the following questions briefly.
(a)What are the four major domains of the earth?
(b)Name the major continents of the earth.
(c)Name the two continents that lie entirely in the Southern Hemisphere.
(d)Name the different layers of atmosphere.
(e)Why is the earth called the ‘blue planet'?
(f ) Why is the Northern Hemisphere called the land Hemisphere?
(g) Why is the biosphere important for living organisms?
Fill in the blanks with appropriate words to complete each sentence:
(i) The South Pole lies almost at the centre of………………..
(ii) Africa is the second largest continent after ……………..
(iii) The world's longest river the Nile flows through ………………
(iv) The hydrosphere comprises water in the form of………………. , water and ………….
(v) The Arctic Ocean is connected with the Pacific Ocean by a narrow stretch of shallow water known as ……………
(vi) The Pacific Ocean is …………. in shape.
(vii)’ The Coastline of Atlantic Ocean is highly ……………….
(viii) Europe lies to the …………. of Asia.
Fill in the blanks.
(a)The deepest point on the earth is ……….. in the Pacific Ocean.
(b)The……… Ocean is named after a country.
(c)The……… is a narrow contact zone of land, water and air that supports life.
(d)The continents of Europe and Asia together are known as…………….
(e)The highest mountain peak on the earth is…………….
Collect pictures of expeditions to the Himalayas. Write about the kind of equipment carried by the climbers for protection against sunshine, temperature and the lack of air.
State whether these sentences aretrue (T) or false (F).
(i) The shape of the Pacific Ocean is almost triangular.
(ii) A veiy small part of Africa lies in the Northern Hemisphere.
(iii) The level of seawater remains the same everywhere.
(iv) Air moves from low pressure to high pressure.
(vi) Carbon dioxide is an important constituent of air.
(vii) The atmosphere is composed mainly of nitrogen and oxygen.