Maharashtra Board Class 5 EVS Part I Chapter 3 The Earth and its Living World PDF Download

The Earth and its Living World

Can You Tell?

1. Where do you get water from?

2. Where do we lay the foundation of buildings?

3. What need do we meet through breathing?

4. From where does the earth get light and heat?

On the surface of the earth, we find land in some places and water in others. The earth is surrounded by the atmosphere. There are living things on land, in water and in the air. The sun is the cause of many natural processes on the earth. Water, land and air constitute envelopes of the earth, namely, the hydrosphere, lithosphere and atmosphere. The biosphere spreads in all the other three spheres.

The Lithosphere and the Hydrosphere

The earth's crust is hard. It is mainly made of rock.

When we travel in hilly regions, we see layers of soil and rock along roadcuts. We see grassy expanses of land in some places and only sand in others. The land is covered with crops in some places and with forests in others. Sometimes we get to see the deeper layers of soil into which tree roots spread. At others we see rocks split apart by the tree roots. There are gentle mountain slopes as well as sheer cliffs of rock. All these land features are a part of the earth's lithosphere. Much of the earth's surface is occupied by water. The lithosphere extends under this water too.

About a third of the surface of the earth consists of land. A vast continuous stretch of land is called a continent. The land on earth is divided into seven continents. They are Asia, Europe, Africa, North America, South America, Antarctica and Australia. Asia is the largest continent and Australia the smallest.

The land is not even in all places. The unevenness gives different shapes to the land in different places. They are called landforms. In the picture above you can see some landforms like the plain, hill, mountain, etc.

Teacher's Note

The lithosphere is the hard outer layer of the earth where we live and build our homes. Just like the ground we walk on in India is part of the lithosphere, so are the Himalayas and all the oceans below.

Exam Trick

Remember: Lithosphere = Land and rocks. Hydrosphere = Water. Think of "lith" meaning stone, just like "lithograph" is written on stone.

Points to Remember

Lithosphere is the hard crust of the earth made of rock and soil.
Hydrosphere is all the water on earth - oceans, rivers, lakes and ice.
About one-third of earth is land and two-thirds is water.
There are seven continents on earth.
Landforms are different shapes of land like mountains, plains and hills.

Two-thirds of the earth's surface is covered with water. Most of this water is in the oceans. Ocean water is salty. There are five oceans, namely, the Atlantic, Pacific, Arctic, the Southern Ocean and the Indian Ocean. The land along the margins of an ocean is called the coastal region. Water bodies of different shapes and sizes are formed along the coast, for example, sea, bay, strait, gulf, creek, etc. These water bodies are part of the ocean.

Surface Water

There are many streams of water flowing over the land. This water is not salty but fresh. These streams of water may be rills, brooks, streams or rivers. Rills are the smallest and rivers, the biggest.

Rills, brooks, streams join each other to form rivers. Rivers which join to make a bigger river are called its tributaries. In some places, a river cascades down a sudden drop. This forms a 'waterfall'. All rivers eventually flow into the ocean.

Lakes: A water body formed by water collecting naturally in a low-lying area of land is called a lake.

Water in the form of ice: Water particles in the clouds freeze and in cold regions, they come down in the form of snow. When layers of snow pile up on the ground, they form ice. When such layers of ice pile up in a low-lying area, they become enormous in size. This huge mass slips down a slope at a very slow speed. This is called a glacier.

There are also huge blocks of ice floating in the sea. They are called icebergs.

Groundwater: Besides these water bodies on the earth's surface, there is a lot of water stored in the underground layers of rock. It is called groundwater. We reach it by means of dug wells and bore wells. Many lakes and wells get water from underground springs.

The water or ice that occupies the earth's surface, groundwater and the water vapour in the atmosphere together form the earth's hydrosphere.

Teacher's Note

Surface water includes all the water we see - rivers, lakes and oceans. In India, the Ganges River and the Western Ghats are important water sources that we depend on every day.

Exam Trick

Remember: Rivers = Fresh water. Oceans = Salty water. Think of a river flowing from mountains to the sea - that journey shows how water moves on earth.

Points to Remember

Rivers are formed when rills and brooks join together.
Tributaries are small rivers that join bigger rivers.
Lakes are formed when water collects in low areas of land.
Glaciers are huge sheets of ice that move slowly down mountains.
Groundwater is water stored under the ground that we get from wells.

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