STD 5: CHAPTER 7: IMPORTANCE OF WATER, EXERCISE QUESTION AND ANSWERS

 

A.     FILL IN THE BLANKS.

1.      Water helps in _______ of food in animals.

Ans: digestion

2.      Animals living in water are called _________.

Ans: aquatic animals

3.       Animals which can live both in water and on land, are called _________.

Ans: amphibious animals

4.       Water, trapped between underground rocks, is called ________.

Ans: ground water

5.      ______ and ______ are aquatic plants.

Ans: duckweed and lotus

B.      WRITE TRUE OR FALSE FOR THE FOLLOWING STATEMENTS.

 

1.      Water is required for germination of seeds.                                                                 True

2.      Ground water can be drawn up by a hand pump.                                                       True

3.      About 50% of water is present in seas and oceans.                                                    False

4.      Octopus is an amphibious animal.                                                                                  False

5.      River water is purified for drinking purpose.                                                                True

 

C.      TICK THE CORRECT OPTION.

 

1.      About 97% of water is present in -

(a)   Seas and oceans                (b) lakes         (c) ponds           (d) glaciers

      Ans: seas and oceans

2.      Plants absorb water from the soil with the help of -

(a)   stem         (b) leaves         (c) branches         (d) roots

      Ans: roots

3.      A rehat is used for-

(a)   Supplying water through taps.

(b)   Purifying river water          

(c)    Drawing out ground water for irrigation      

(d)   Absorbing water from the soil

       Ans: drawing out ground water for irrigation

4.      An example of an amphibious animal is-

(a)   fish                           (b) frog

(c)    hydrilla                    (d) duckweed

      Ans: frog

D.     ANSWER THE FOLLOWING QUESTIONS IN BRIEF.

 

1.      Name any two water bodies that exist on the surface of earth.

Ans: Seas and oceans are the water bodies that exist on the surface of earth.

2.      What are animals living in water known as? Write names of two such animals.

Ans: The animals living in water are known as aquatic animals. Examples are, fish and octopus.

3.      What are amphibious animals?

Ans: Animals, which can live both in water and on land, are called as amphibious animals.

4.      Write names of four aquatic plants.

Ans: Four aquatic plants are, water lily, duckweed, lotus and water hyacinth.

5.      How do plants absorb water from the soil?

Ans: The plants absorb water from the soil with the help of their roots.

6.      State two common methods of drawing out ground water.

Ans: Two common methods of drawing out ground water are using a rehat or a pulley.

E.      ANSWER THE FOLLOWING QUESTIONS.

 

1.      Besides its domestic use, state three other uses of water.

Ans: Besides its domestic use, water is also used for, i) irrigating the fields,

                                                                                                 ii) generating electricity and  

                                                                                                 iii) transportation

2.      How does water help in excretion of waste material from animal bodies?

Ans: i) The animal body produces waste materials.

ii) These waste materials get dissolved in water and are excreted in the form of urine or sweat.

3.      List any four ways in which water is important for plants.

Ans: i) Water provides nutrients to plants in dissolved form.

ii) Water also helps in transporting nutrients to various parts of the plant.

iii) Plants require water for photosynthesis process.

iv) Plants require water for germination of seeds.

4.      How can ground water be drawn out through tubewells?

Ans: i) In a tubewell, a long pipe is inserted deep into the ground where it dips below the ground water level.

ii) Water is then drawn up by using a hand pump or an electric pump.

5.      What is a stepwell?

Ans: i) A stepwell is a well having steps on all sides.

ii) This enables people to go down to fetch water.

6.      How is water supplied in cities?

Ans: i) There are well-planned water supply systems that supply water to homes and offices in the cities.

ii) In such systems, the river water is usually purified by a series of processes that make it fir for drinking.

iii) This purified water is then sent to homes and offices through a network of pumps and pipes.