NCERT Solutions for Ch 11 Nature’s Treasures Class 6 Science
Book Solutions1
What will happen if the Sun is not visible for a few days?
i. We may have to depend on artificial lighting during day time also.
ii. ______________
iii. ______________
i. We may have to depend on artificial lighting during day time also.
ii. ______________
iii. ______________
Answer
ii. With no sunlight, photosynthesis would stop, but that would only kill some of the plants—there are some larger trees that can survive for decades without it.iii. There will be no natural light and heat hence stopping many natural phenomenons like evaporation, transpiration, condensation etc.
Activity
2
What are the consequences of cutting a large forest area? Make a presentation or do a role play, or write a story or a poem that shows what could happen if we continue to cut down trees in our forests.
Answer
The loss of trees and other vegetation can cause climate change, desertification, soil erosion, flooding, increased greenhouse gases in the atmosphere, and a lot of problems for humans Presentation/Play/Story or Poem: Do it yourself.
Activity
3
Figure shows items related to natural resources. Match them with their jumbled up names. Make another table and write the names of these resources. Classify these resources as renewable or non-renewable.
Answer
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4
State whether the following statements are True [T] or False [F]. If False, correct them.
(i) Nature has all the resources to meet human needs.
(ii) Machines are a resource found in nature.
(iii) Natural gas is a non-renewable resource.
(iv) Air is a renewable resource.
(i) Nature has all the resources to meet human needs.
(ii) Machines are a resource found in nature.
(iii) Natural gas is a non-renewable resource.
(iv) Air is a renewable resource.
Answer
(i) True(ii) False
Correct Statement: Machines are human-major resources.
(iii) True
(iv) True
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5
Fill in the blanks using the most appropriate option
(i) A fuel that is commonly used in two wheelers like scooters or bikes is ______________
(a) Kerosene
(b) Petrol
(c) Diesel
(d) LPG
(i) A fuel that is commonly used in two wheelers like scooters or bikes is ______________
(a) Kerosene
(b) Petrol
(c) Diesel
(d) LPG
Answer
(b) Petrol
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6
(ii) An example of a renewable resource is ______________
(a) Coal
(b) Water
(c) Natural gas
(d) Petrol
(a) Coal
(b) Water
(c) Natural gas
(d) Petrol
Answer
(b) Water
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7
Classify the following as renewable or non-renewable resources— coal, natural gas, forests and minerals.
Answer
Renewable resources: ForestsNon-renewable resources: Coal, natural gas and minerals
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8
Why do we say that petroleum is a non-renewable resource?
Answer
Petroleum takes millions of years to form. It is found in limited quantities and once used, it gets exhausted. It cannot be produced or replenished within a reasonable period of time. Hence, petroleum is called non-renewable resource.
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9
It is difficult to regrow forests. Justify this statement.
Answer
Though forests are renewable natural resource and nature keeps on renewing them. But indiscriminate felling of trees makes it difficult to regrow forests. Forest are being destructed to use the land for cultivation, building houses, factories, making space for cattle grazing, extraction of oil, mining, construction of dams or to obtain wood for making furniture and using it as fuel. If we keep on doing so, it would become difficult to regrow forests.Additionally, the ecological balance and biodiversity that develop in a forest over centuries cannot be easily replicated. Therefore, we must preserve and use forests responsibly so that they get enough time to regenerate.
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10
Make a list of five daily activities in which you use natural-resources. Suggest ways by which you can reduce their use.
Answer
• We use water for watering plants.• We can avoid using a hose pipe for watering plants as a lot of water is wasted through it.
• We use water for taking shower.
• Instead of shower, we can take bath using a bucket and mug.
• We use fuels in vehicles.
• We can use public transport or carpool to save fuel.
• We use electricity and coal is used to generate electricity.
• We can use stairs (at least up to 3 floors ) to climb instead of taking lift.
• We use electricity to run fans and lights. We should switch off fans and lights in unoccupied rooms.
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11
List four activities that are possible due to the presence of air.
Answer
Activities that are possible due to the presence of air:• Breathing
• Flying kites
• Inflating tyres and balloons
• Drying clothes
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12
How can you contribute towards enhancing the green cover of your locality? Make a list of actions to be taken.
Answer
• I can contribute towards enhancing the green cover of my locality by adopting following practices:• I can plant more and more trees and help clean up parks, playgrounds, and other green areas by picking up litter.
• I can take care of the plants and trees growing in or around my locality.
• I can encourage the people in my locality to plant more trees by informing them about the importance of growing trees.
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13
In the given illustration, we see that food is being cooked. Answer the following questions—
(i) What type of energy is being used for cooking?
(ii) Name one benefit and one drawback of using this type of energy for cooking.
Answer
(i) Solar energy or Sun’s energy(ii) Benefit: Solar energy does not cause pollution.
Drawback: This energy is not available during rainy or cloudy weather.
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14
Cutting down trees on a large scale impacts the quality of the soil. Why do you think it is so?
Answer
Yes, large scale cutting of trees causes soil erosion. The roots of trees help to hold the soil. When trees are cut down, the roots are no longer holding the soil together and physical factors such as wind and water can easily displace the soil. Besides this, the leaves that fall from the trees decay and enrich the soil with nutrients. These nutrients are used by the plants and trees growing there.
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15
Explain two ways in which human activities pollute the air. Propose one action which can help in reducing air pollution.
Answer
We use automobiles to travel and fossil fuels are used as a source of energy. Burning of fossil fuels in automobiles releases harmful smoke and gases which cause air pollution. Another cause of air pollution is burning of leaves, trash, and other materials. On burning, these materials also release harmful gases in the air and cause air pollution. Carpooling and public transit are excellent ways to reduce air pollution. No-fuel options like walking and biking are also good options to reduce air pollution.
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16
A family uses solarpanels to generate electricity, a gas stove to cook food and a windmill for pumping waterfrom a well. What would happen if there were no sunlight for a week?
Answer
This family uses solar energy to generate electricity. If there were no sunlight for a week, electricity generation will stop.
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17
Fill up the blanks using the following terms— (fossil fuels, forest, air, petroleum, coal, water and non-renewable resource)
Answer
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18
There is an increasing demand of trees to meet the requirements of industries and for housing. Therefore, trees are being felled. Is it justified? Discuss and prepare a brief report.
Answer
No, it is wrong to cut the trees for self-need and to meet the increasing demands of human populations.Reasons for the same are given below:
• Forests are a natural home for many wild animals, including birds and insects. Forests provide food and shelter to them.
• Trees provide us with fresh oxygen for breathing.
• Trees control soil erosion.
• Trees also protect us from various natural calamities like drought, flood, etc.
• Trees provide us with food which is the basic need of humans.
• We should try to plant more and more trees to keep our ecological balance.
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19
Propose a plan to use less water in your school. What steps would you take to. make this plan happen and how would it help the environment?
Answer
Water is an important natural resource. We should always try to conserve it. We can take following actions to conserve water in our school:• We should fill our drinking water cup half. If required, we can take more.
• We should close taps properly after use.
• We can reduce the wastage of water by not flushing the toilet unnecessarily.
• Water used for washing hands can be reused for watering plants.
• We can get the leaky taps and pipes fixed.
• We can set up roof-top rainwater harvesting in the school.
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