Text Book Page No. 33
Why water is important for us ?
Water is important for us because
- Maximum part of our body is made up of water.
- It is essential for plants growth.
- We use it for drinking. Without water the existence of plants, animals is not possible and this will create threat to human existence too.
Suggest three ways in which water can be conserved in your home and two ways in your school.
Ways to conserve water at home :
- Do not throw away water that has been used for washing vegetables, rice or dais. Use it to water plants or to clean the floors.
- Avoid flushing of toilet unnecessarily.
- When washing the car, use water from a bucket and not a hosepipe.
Ways to conserve water at school :
- Replacement of old/leaking service pipes.
- Regular checking of taps used for drinking water. Leaking taps should be immediately removed.
Exercise Questions and Answers
Answer the following questions :
(1) What is precipitation?
Precipitation is the deposition of moisture from the atmosphere onto the earth’s surface. This may be in the form of
(2) What is water cycle?
The process by which water continually changes its form and circulates between oceans, atmosphere and land is known as the water cycle.
(3) What are the factors affecting the height of the waves?
(a) High speed winds
(c) volcanic eruption
(d) underwater landslides
(4) Which factors affect the movement of ocean water ?
(a) Temperature and
(b) Rotation of the earth
(5) What are tides and how are they caused?
The rhythmic rise and fall of ocean water twice a day is called a tide. Tides are caused due to the gravitational pull exerted by the sun and the moon on the earth’s surface.
Tick the correct answer.
(1) The process by which water continually changes its form and circulates between oceans, atmosphere and land
(a) Water cycle
(c) Ocean currents
(a) Water cycle
(2) Generally the warm ocean currents originate near
(c) None of these
(3) The rhythmic rise and fall of ocean water twice in a day is called
(b) Ocean current
Match the following :
|Caspian Sea||Largest lake|
|Tide||Periodic rise and fall of water|
|Tsunami||Strong seismic waves|
|Ocean currents||Streams of water moving in definite paths|
(1) Ocean water is salty.
Because it contains large amounts of dissolved salts.
(2) The quality of water is deterioting.
The quality of water is deteriorating because
- Garbage we throw in the river.
- Chemicals from industries and polluted water.
- Remains of the harmful insecticides and pest resistants flowing in from the fields.
- Unburnt or half burnt corpses of men and animals thrown in water bodies.
Be a detective
(1) The name of one river is hidden in each of the sentences below. Spot it.
Example : Mandra, Vijayalakshmi and Surinder are my best friends.
(a) The snake charmer’s bustee, stables where horses are housed, and the piles of wood, all caught fire accidentally. (Hint : Another name for River Brahmaputra)
(b) The conference manager put pad, material for reading and a pencil for each participant. (Hint: A distributary on the Ganga-Brahmaputra delta)
(c) Either jealousy or anger cause a person’s fall. (Hint : Name of a juicy fruit!)
(d) Bhavani germinated the seeds in a pot. (Hint: Look for her in West Africa)
(e) “I am a zonal champion now,” declared the excited athletic. (Hint: The river that has the biggest basin in the world)
(f) The tiffin box rolled down and all the food fell in dusty potholes. (Hint : Rises in India & journeys through Pakistan)
(g) Malini leaned against the pole when she felt that she was going to faint. (Hint : Her delta in Egypt is famous)
(h) Samantha mesmerised everybody with her magic tricks. (Hint : London is situated on her estuary)
(i) “In this neighbourhood, please don’t yell! Owners of these houses like to have peace,” warned my father when we moved into our new flat, (Hint: colour)
(j) ‘Write the following words. Marc ! “On”, “go”, “in” …. said the teacher to the little boy in KG Class. (Hint : Rhymes with ‘bongo’)
Now make some more on your own and ask your classmates to spot the hidden name. You can do this with any name : that of a lake, mountains, trees, fruits, school items, etc.
Students do themselves.
Carry on Detective
(2) With the help of an atlas, draw each river which you discovered in For Fun (i), on an outline map of the world.