Major Domains of the Earth

Q36. How many continents are there on the earth? Name them.

Ans. There are seven major continents separated by large water bodies. These continents are – Asia, Europe, Africa, North America, South America, Australia and Antarctica.

Q37. Write is the main reason of air pollution.

Ans. Emission from industries, thermal power plants and vehicles, pollutes the air. Carbon dioxide (CO₂) is an important constituent of air but increase in the amount of CO₂ leads to global warming.

Q38. What is ‘Atmosphere’? Why atmosphere is so important?

Ans. The earth is surrounded by a layer of gas called the atmosphere. This thin blanket of air is an integral and important aspect of the planet. It provides us with the air we breathe and protects us from the harmful effects of sun’s rays.

Q39. Why do mountaineers carry oxygen cylinders with them?

Ans. The climbers experience problems in breathing as density of air decreases rapidly as we go up. That’s why they carry oxygen cylinders with them to be able to breathe at high altitudes.

Q40. Write a short note on the continent – Antarctica.

Ans. Antarctica, completely in the Southern Hemisphere, is a huge continent. The South Pole lies almost at the centre of this continent. As it is located in the South Polar Region, it is permanently covered with thick ice sheets. There are no permanent human settlements. Many countries have research stations in Antarctica.

Q41. What is the height of the Mt Everest? Who were the first men to climb the highest mountain peak Mt. Everest on the planet earth on 29th May, 1953?

Ans. The highest mountain peak Mt. Everest is 8,848 metres above the sea level. Edmund Hillary (New Zealand) and Tenzing Norgay Sherpa (India) were the first men to climb the highest mountain peak Mt. Everest on the planet earth on 29th May, 1953.

Q42. Write about Pacific Ocean.

Ans. The Pacific Ocean is the largest ocean. It is spread over one-third of the earth. Mariana Trench, the deepest part of the earth, lies under the Pacific Ocean. The Pacific Ocean is circular in shape. Asia, Australia, North and South Americas surround it.