STD - 4, CHAPTER - 4 : PLANTS AROUND US, EXERCISE QUESTIONS AND ANSWERS

 

A.     FILL IN THE BLANKS.

1.      Plants, growing on hills, are tall, straight and have a _____ shape.

Ans: Conical

2.      ______ and ______ are two of the trees that grow on plains.

Ans: Mango, Banyan

3.      Breathing roots are also called ______ roots.

Ans: aerial roots

4.      ______ is an underwater plant.

Ans: Hydrilla

5.      Lotus stem is eaten as a _______.

Ans: vegetable

B.      MATCH THE FOLLOWING:

1.      Evergreen trees                             (a) rice

2.      Needle-like leaves                        (b) cactus

3.      No leaves                                        (c) mangrove

4.      Breathing roots                             (d) aquatic plant

5.      Air filled cavities                           (e) rubber and teak

6.      A cultivated crop                           (f) pine and cedar

      Ans:

1.      Evergreen trees                             (e) rubber and teak

2.      Needle-like leaves                        (f) pine and cedar

3.      No leaves                                        (b) Cactus

4.      Breathing roots                             (c) mangrove

5.      Air filled cavities                            (d) aquatic plant

6.      A cultivated crop                           (a) rice

 

C.      TICK THE CORRECT OPTION.

1.      It is a free floating plant -

(a)   Water hyacinth        (b) hydrilla          (c) coconut        (d) lotus

      Ans: Water hyacinth

2.      These are unwanted plants -

(a)   Cactus        (b) Grass          (c) Mangroves        (d) Weeds

      Ans: Weeds

3.      It can survive in soil with very little water -

(a)   Banyan        (b) Teak          (c) Rubber        (d) Cactus

      Ans: Cactus

D.     ANSWER THE FOLLOWING QUESTIONS IN BRIEF.

1.      What are terrestrial plants?

Ans: Plants which grow on land, are called terrestrial plants.

2.      How does the conical shape help the plants of hills?

Ans: The conical shape of these trees does not allow snow to get deposited on them.

3.      Name two trees growing in hot and wet regions.

Ans: Two trees growing in hot and wet regions are - Teak, rubber, coconut, pepper, cotton, rice and banana. (any two)

4.      Name an underwater plant. What kind of leaves does it have?

Ans: Hydrilla is an underground plant. It has pointed and strap-like leaves.

5.      What is ploughing? 

Ans: The process of digging the soil or loosening the soil, is called ploughing.

E.      ANSWER THE FOLLOWING QUESTIONS.

1.      List the different habitats of terrestrial plants.

Ans: The different habitats of terrestrial plants are,

i) Hills

ii) Plains

iii) Hot and Wet regions

iv) Marshy areas

v) Desert areas

2.      How is cactus plant able to grow in desert conditions?

Ans: i) It can survive in soil that has very little water.

ii) It has a green stem and well developed roots. The stem stores water.

iii) Cactus plant has spines instead of leaves.

3.      What are aquatic plants? State their types and give two examples of each type.

Ans: i) Plants, found in water, are called aquatic plants.

ii) Aquatic plants are of two types:

a)      Floating Aquatic Plants

- Free floating plants (Two examples are: Water lettuce and Water hyacinth)

- Fixed Aquatic Plants (Two examples are: Lotus and Water lily)

b)     Underwater Plants (Two examples are: Hydrilla and Kelps)

 

4.      What are cultivated plants?

Ans: i) Those plants which are grown in the fields by the farmers, are called as cultivated plants.

ii) The cultivated plants grow and give us the desired products.

iii) Examples: Sugarcane, maize, wheat and rice.

5.      Why should weeds be removed from the fields?

Ans: i) The undesirable plants in the field are called as weeds.

iii) They can harm the growth of cultivated plants.

ii) Weeds are removed so that they do not consume water and fertilisers meant for the main crop