What are fossils? How are fossils formed and how is their age determined?
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1
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543
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April 4, 2019
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Explain the harmful effects of ozone depletion on Earth
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1
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558
|
April 4, 2019
|
(a) Why should ozone layer be protected to save the environment?
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1
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5300
|
April 4, 2019
|
Give reason to justify the following: (a) The existence of decomposers is essential in a biosphere
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1
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5808
|
April 4, 2019
|
“Energy flow in a food chain is unidirectional. Justify this statement
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1
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1079
|
April 4, 2019
|
“Our food grains such as wheat and rice, the vegetables and fruits
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1
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1016
|
April 4, 2019
|
(a) What is an ecosystem? List its two main components
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1
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1082
|
April 4, 2019
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How is ozone formed in the higher level of atmosphere?
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1
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2835
|
April 4, 2019
|
What is “Green House Effect”? State two advantages and two disadvantage of this effect
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1
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617
|
April 4, 2019
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“Reuse is better than recycling of materials”. Give reason to justify this statement
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1
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1636
|
April 4, 2019
|
List two reasons to show that the existence of decomposers is essential in an ecosystem
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1
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2450
|
April 4, 2019
|
Why is Government of India imposing a ban on the use of polythene bags?
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1
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932
|
April 4, 2019
|
List the products of combustion of fossil fuels ? What are their adverse effects on the environment?
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1
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768
|
April 4, 2019
|
An environmentalist on visit to your school suggested the use of three R’s to save the environment
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1
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2460
|
April 4, 2019
|
How are the following caused and what is the effect of each of them on our environment? (i) Depletion of ozone layer (ii) Acid rain
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1
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660
|
April 4, 2019
|
List any four practices which help in protecting our environment
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1
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1182
|
April 4, 2019
|
Why is conservation of wildlife considered important for us? Give any two reasons
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1
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981
|
April 4, 2019
|
What is acid rain? Mention its two harmful effects
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1
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1280
|
April 4, 2019
|
Distinguish between biodegradable and non-biodegradable wastes. Give one example of each
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1
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576
|
April 4, 2019
|
How does depletion of soil takes place? Suggest two ways to prevent it
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1
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597
|
April 4, 2019
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Describe how green house effect may cause atmospheric heating?
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1
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538
|
April 4, 2019
|
Waste of which of the following two materials in more polluting? Polythene or paper. Give reasons for your answer
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1
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1424
|
April 4, 2019
|
Write one negative effect, on the environment of affluent lifestyle of few persons of a society?
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1
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964
|
April 4, 2019
|
The depletion of ozone layer is a cause of concern why?
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1
|
1928
|
April 4, 2019
|
Why should biodegradable and non-biodegradable wastes be discarded in two separate dust bins?
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1
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1113
|
April 4, 2019
|