class iv science "plant around us"

Plants:Around us

A.1conical

2.mango &banyan

3.pneumatophore/aerial roots

4.HYDRILLA

5.vegetable(KAMAL KAKARI)

D1.What are terrestrial plants?

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

D2.How does the conical shape help the plants of hills?

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

D3.Name two trees growing in hot and wet regions.

Ans: Trees like rubber and teak grow in hot and wet regions.

D4.Name an underwater plant. What kind of leaves does it have?

Ans:Hydrilla is an example of underwater plant. It has pointed and strap-like leaves..

D5.what is ploughing?

Ans:The preparation of soil by digging with help of wooden  plough or tractor  to lose  & make  soft is called ploughing.

E1.List the different habitats of terrestrial plants?

Ans:The habitats of terrestrial plants are:

i)hills ii)plains iii)Desert iv)hot & wet regions v)Marshy areas.

E2.How is cactus plant able to grow in desert conditions?

Ans:The climate of desert is  dry &hot .It is filled with sand. Cactus plant converts its leaf into spine to reduce water loss through stomata. The stem of cactus plant is thick, green and fleshy so it can prepare food for the plant. The stem also store water for the plant.

E3.What are aquatic plants? State their types and give two examples of each type. Ans: Plants which grows in water are called aquatic plants. Aquatic plants are of three types such as fixed, free floating & under water plant.

Examples: Fixed-aquatic plants---lotus, lily

Free floating----water hyacinth, duckweed                   

Underwater---hydrilla, tape grass

E4.What are cultivated plants?                                               

Ans: The plants like rice, maize & sugarcane which are grown in large scale by farmers are called cultivated plants.

E5.Why should weeds be removed from the fields?

Ans: The undesirable plants which grow along with the cultivated plants are called weeds. These undesirable plants compete with cultivated plant for nutrient, air, water, space & light and harm the growth of main crops, so they should be removed from the fields.

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In fibrous roots all roots are much similar in size.

E3.State two main functions of roots?

Ans:The two main function of roots are fixation and absorption  of water and minerals.

E4.In what ways are the  roots   of banyan tree and maize are  special.?

Ans: The main root of banyan and maize tree are not strong enough support the tree. The special  prop root which grow from the branches gives extra support to the main plant.