Explain how forests prevent floods.
Forests contains a variety of flora and fauna. They act as the natural absorber of the water. Forests allow rainwater to seep into the soil. In the absence of trees, the rainwater directly hits the ground, this may leads to flood. However, the presence of trees does not allow rainwater to hit the ground directly. It hits the ground slowly. Before flooding, the rainwater seep through the ground. Tree's roots helps to bind the soil whereas if there are no trees then soil erosion occurs by the heavy rainfall. That's why we can say that forest prevents floods.
Popular Questions of Class 7 Science
- Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
- Q:-
Sketch the cross section of soil and label the various layers.
- Q:-
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human bodyDown
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water - Q:-
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
- Q:-
Sketch the reproductive parts of a flower.
- Q:-
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil. - Q:-
Describe how crystals of copper sulphate are prepared.
- Q:-
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus - Q:-
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
Recently Viewed Questions of Class 7 Science
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Which type of lens forms always a virtual image?
- Q:-
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
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How do elephant living in the tropical rainforest adapt itself?
- Q:-
Out of the following, which are the two terms related to silk production? Sericulture, floriculture, moriculture, apiculture and silviculture.
Hints:
(i) Silk production involves cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba. - Q:-
State two differences between a convex and a concave lens.
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Explain, with examples, why we find animals of certain kind living in particular climatic conditions.
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Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
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Why do organisms need to take food?
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Name the source from which litmus solution is obtained. What is the use of this solution?
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Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
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